Pulmonary in isolated
vascular response to anaphylaxis canine lungs
TOSHISHIGE YOSHIKAZU
SHIBAMOTO, TETSUYA HAYASHI, MATSUDA, MICHIKO KAWAMOTO,
JR., FUMITOSHI SAWANO, AND SHOZO KOYAMA
YUKA
SAEKI,
Department of Physiology, Division 2, Shinshu University School of Medicine, Matsumoto, Nagano 390, Japan Shibamoto, Toshishige, Tetsuya Hayashi, Jr., Fumitoshi Sawano, Yuka Saeki, Yoshikazu Matsuda, Michiko Kawamoto, and Shozo Koyama. Pulmonary vascular response to anaphylaxis in isolated canine lungs. Am. J. Physiol. 263 (Regulatory Integrative Comp. Physiol. 32): Rl024-R1029, 1992.-We determined changes in vascular resistance and microvascular permeability during anaphylactic reaction in isolated canine lungs perfused at constant pressure with autologous blood. In lungs with anaphylaxis induced by an intra-arterial injection of Ascaris suum antigen (10 mg), pulmonary vascular resistance and capillary pressure assessed as double occlusion pressure increased transiently by 10 times and 6.3 mmHg, respectively. Pre- to postcapillary vascular resistance ratio decreased from 0.89 ,t 0.05 to 0.21 t 0.06, suggesting predominant pulmonary venoconstriction. In lungs perfused in the antidromic direction from the pulmonary vein to the artery, anaphylaxis caused marked precapillary vasoconstriction, consistent with pulmonary venoconstriction. Vascular permeability assessed using the capillary filtration coefficient and isogravimetric capillary pressure did not change significantly for 3 h in either group. No changes were found in any variables in the saline-injected control lungs. The final weight of the anaphylactic lungs was significantly greater than that of the control lungs. Thus we conclude that anaphylaxis in isolated canine lung produces an increase in capillary pressure due to pulmonary venoconstriction without significant changes in vascular permeability. Pulmonary edema accompanied by anaphylactic hypotension may result from an increase in pulmonary hydrostatic intravascular pressure but not an increase in pulmonary vascular permeability. capillary filtration coefficient; pulmonary edema; pulmonary
isogravimetric capillary venoconstriction
pressure;
that pulmonary edema sometimes develops during anaphylactic shock (2, 5, 12, 18, 26). However, the exact mechanism responsible for the pathogenesis of anaphylaxis-induced pulmonary edema remains obscure. Pulmonary hypertension and increased pulmonary vascular resistance are found in anaphylactic shock of humans (25) and animals (9, 16). Various chemical mediators responsible for anaphylactic reaction could induce an increase in pulmonary arterial pressure (16). However, one of the most important determinants of pulmonary edema is an increase in pulmonary capillary pressure (27). Alveolar hypoxia causes pulmonary vasoconstriction. However, it does not affect lung fluid filtration because a site responsible for vasoconstriction is located in predominantly precapillary vessels (3, 7). However, it is not known whether pulmonary capillary pressure increases during anaphylaxisinduced pulmonary hypertension. With respect to changes in pulmonary microvascular permeability in the anaphylactic response, there are also no consistent concepts. Carlson et al. (5) reported that an increase in pulmonary vascular permeability was IT HAS BEEN KNOWN
observed in a patient with anaphylactic shock as based on the finding of increased protein concentration of the airway fluid compared with that of plasma. However, an increase in leakage of albumin was observed only in bronchial vessels but not pulmonary parenchymal vessels in experimental anaphylactic lungs of rats (22). Accordingly, it is not clear whether pulmonary edema associated with anaphylaxis is caused by an increase in hydrostatic pulmonary capillary pressure or an increase in pulmonary microvascular permeability. Therefore, the purpose of the present study was to determine if anaphylactic reaction induced by Ascaris suum antigen in the isolated blood-perfused canine lungs causes an increase in microvascular permeability and to define changes in the distribution of pulmonary vascular resistance of the lung with anaphylaxis. METHODS Isolated
Lung Preparation
Fifteen mongrel dogs (7-16 kg) were anesthetized with pentobarbital sodium (25 mg/kg iv). They were intubated and mechanically ventilated at a tidal volume of 15-20 ml/kg. The isolated lung preparation and perfusion system have been basically described (17, 23, 24). Catheters were placed in the left jugular vein and in the left carotid artery. Ten minutes after treatment with heparin sodium (500 U/kg iv) to avoid coagulation, the dog was rapidly bled through the carotid artery catheter. After left thoracotomy, the left lower lobe was excised near the hilum and was weighed. Plastic cannulas were secured in the pulmonary artery and vein and the lobar bronchus. Thereafter, perfusion was begun within 15 min after the excision of the lung. Lung Perfusion
System
Figure 1 shows a diagrammatic representation of the isolated lung perfusion system. The cannulated lobe was suspended from an electric balance (LF-600, Murakami Koki) and perfused at constant perfusion pressure with shed blood that was pumped from the outflow reservoir through a heat exchanger (37°C) into the inflow reservoir. Airway pressure was maintained at a constant level of 3 cmH,O. An overflow tube was connected to the inflow and outflow reservoirs to maintain a constant arterial perfusion pressure. The height of each reservoir could be adjusted independently to maintain arterial and venous pressures at any steady level. The perfused blood was oxygenated in the outflow reservoir by continuous bubbling with 95% 02-5% CO,. Pulmonary arterial (P,) and venous (P,) pressures were measured using pressure transducers that were placed on the reference points at the level of the hilum of the lung. Blood flow (&) was measured with an electromagnetic flowmeter (MFV 1200; Nihon Kohden, Tokyo, Japan), and the flow probe was positioned in the venous outflow line. Lung weight was continuously monitored and displayed on the physiograph. P, and P,
0363-6119/92 $2.00 Copyright 0 1992 the American Physiological Society R1024 Downloaded from www.physiology.org/journal/ajpregu by ${individualUser.givenNames} ${individualUser.surname} (129.215.017.190) on January 11, 2019.
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Preparation
AIR
ARTERIAL RESERVOIR I
HEAT
EXCHANGER
ROTARY PUMP
TR
Fig. 1. Diagram
of perfusion
of
Pulmonary
Vascular
Permeability
Capillary filtration coefficient. The capillary filtration coefficient (J&J was used as an index of microvascular permeability (8) and assessed by simultaneously increasing P, and P, by 6-8 mmHg from an isogravimetric state and observing the increase in weight of the lung. The sudden increase in vascular pressure caused a rapid weight gain of the lobe due to an increase in blood volume of the lung. This was followed by a gradual and prolonged weight gain that was attributed to transcapillary fluid filtration (8). The weight gain rate (dw/dt) at each minute following the increase in pressure (t = 0) was plotted as a semilogarithmic function with time, and the slow phase of the weight transient was extrapolated to time 0. When the lung was not isogravimetric but was gaining weight, this extrapolated rate of weight gain was subtracted by the weight gain rate 2 min just before Kf,, determination. The extrapolated rate of weight gain [ (dw/dt) t=o] was then divided by the increase in pulmonary capillary pressure (dP,). Capillary pressure (P,) was measured before and after the increase in vascular pressure using the double vascular occlusion technique (28). &c was normalized to the initial lung weight of 100 g to yield K,,, (in ml min-l cmH,O-l -100 g wet wt-‘) l
l
(0
dp C
Isogravimetric capillary pressure. The isogravimetric capillary pressure (P,:,,i) is the capillary pressure at which the lung neither gains nor loses weight. The prevailing pulmonary capillary pressure was measured using the double occlusion technique (28). The PC,; is determined by the following equation (2)
where 7rc and ri are plasma and interstitial protein oncotic pressures, respectively, Pi is interstitial pressure, and 0 is the capillary osmotic reflection coefficient for proteins. Thus PC,; can be used as an index of microvascular permeability of proteins if plasma protein concentration is constant. A decrease in P, i would indicate a decrease in vascular permeability to proteins because Pi tends to increase with increased filtration. The total vascular (R,), arterial (R,), and venous (R,) resistances were calculated as follows
The &to-R,
R, = (P, - p,>/&
(3
R, = (p, - q/Q
(4
R, = (PC - p,>/Q
(5
ratio (RJR,)
was also determined.
Ascaris
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suum Antigen
Protocol
Hemodynamic parameters of the perfused lung were observed for at least 20 min after the start of perfusion to reach an isogravimetric state at P, of 13-18 mmHg, P, of 2.5-4 mmHg, and a blood flow >0.7 liters mine1 100 g-l. All lobes with a baseline blood flow of ~0.7 liters min. 100 g-l were excluded from the present study. During baseline measurement, Kfc and P, i were determined twice, and the mean values were used as the baseline values. After these baseline measurements, all of the blood-perfused lobes were divided into the following three groups. Control group (n = 5). In these experiments, a 3-ml bolus of saline was injected into the arterial reservoir. Anaphylaxis group with orthodromic perfusion (n = 5). In these experiments, Ascaris suum antigen (10 mg) was diluted with 2 ml saline and was injected into the inflow arterial reservoir as a bolus. Anaphylaxis group with antidromic perfusion (n = 5). In these experiments, after the orthodromic perfusion of the isolated lung was established, the inflow tube was connected to the pulmonary vein and the outflow tube to the pulmonary artery. Thus the blood entered the lung lobe via the pulmonary vein and was withdrawn from the pulmonary artery. The same amount of Ascaris suum antigen as the orthodromic perfusion group was injected into the inflow (venous) reservoir. Kfc was measured at 10, 60, 120, and 180 min after the injection of the antigen or saline in each group. In the lobes that gained weight, vascular pressures were reduced to maintain the lobe in an isogravimetric state and to obtain P, i during the experimental period. However, in both orthodromic perfusion and antidromic perfusion groups, during the initial 30 min after the antigen challenge, the height of both reservoirs was not changed to observe the time course of the original responses. Then, the isogravimetric state was maintained until the end of the experiment. After the end of the experiment, the final weight of the perfused lung was measured, and the final wet weight-to-initial wet weight ratio was determined. l
l
l
Statistical P,i=Pi+a(~,-~i) 7
of
DOG
Ascaris antigen was prepared as previously described (14). Briefly, adult worms of Ascaris suum were triturated in saline and lyophilized. The material was resuspended in saline, further triturated by repeated freeze-pressing, and centrifuged. The supernatant was dialyzed against phosphate-buffered saline (pH 7.0), centrifuged, and stored at -20°C. Protein content was determined by micro-Kjeldahl. Ascaris suum antigen solution was adjusted with saline to obtain the protein concentration of 10 mg/ml. Experimental
system.
were initially adjusted to a level within the normal perfusion range in zone 3 (P, > P, > P,,, where P,, is airway pressure) and to obtain an isogravimetric state (no weight gain or loss). Measurements
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Analysis
All values are expressed as means k SE. Comparisons among all groups and within each group for a given variable were performed using analysis of variance followed by Duncan’s multiple-range test. P values 2.3 mmHg so as to keep the lung at zone 3 conditions. & decreased from the baseline value of 1.32 t 0.17 to 0.301 t 0.14 litersmin- L 100 g-l at 3 min after the
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Table 1. Pulmonary hemodynamics after anaphylaxis in isolated canine lungs Time
Hemodynamic Parameter
Group
n
After
Anaphylaxis,
min
Baseline
3
10
30
60
120
180
P,, cmHzO
Control 5 14.2t0.9 14.lkO.8 14.0t0.8 14.120.8 14.OkO.7 14.2t0.7 14.2t0.7 AI 5 15.8t0.7 20.4+l.l*Ji 20.6~1.0"~ 18.5+1.6*? 16.8tl.5 15.621.4 15.6tl.O &I 5 3.4t0.4 l.lt0.6* 1.6kO.5 2.6k0.4 2.9t0.3 2.8t0.2 2.9t0.3 P,, cmH20 Control 5 3.3kO.l 3.1k0.2 3.ltO.l 3.2tO.l 3.020.2 3.0tO.l 3.2t0.3 AI 5 3.0t0.4 -0.7+0.5*t -0.9+0.5*t 1.4+0.6*-t 2.7t0.3 2.3t0.4 2.620.3 &I 5 12.920.6 16.6t0.5* 15.7kO.7" 14.OkO.6 13.lt0.4 12.9t0.5 13.220.6 &, liter min-l 100 g-l Control 5 1.29t0.17 1.29kO.18 1.30t0.18 1.30t0.17 1.29t0.17 1.26t0.16 1.2lt0.16 AI 5 1.32t0.17 0.30+0.14*t 0.35+0.06*t 0.57+0.10*t 0.61+0.07*t 0.66kO.lO"t 0.62&0.10* AI1 5 1.33kO.13 0.59+0.18*-f 0.67+0.18*-f 1.13kO.15 1.18t0.19 1.20t0.20 1.15t0.20 Values are means t SE; n, no. of lobes. Control, control group; Ai, anaphylaxis group with orthodromic perfusion; An, anaphylaxis group with antidromic perfusion; P,, pulmonary arterial pressure; P,, pulmonary venous pressure; &, pulmonary blood flow. * P < 0.05 from baseline. t P < 0.05 vs. control group. l
l
antigen injection. There followed a recovery toward the preinjection level. In the antidromic perfusion group, changes in P, and P, were opposite to those of the orthodromic perfusion group, with an increase in P, and a decrease in Pa after the antigen challenge. & in this group decreased less than that in the orthodromic perfusion group. No significant changes in hemodynamic variables were found in the control group throughout the experimental period. Figures 2 and 3 show example recordings of responses to injection of Ascaris suum antigen from the orthodromic perfusion and antidromic perfusion groups, respectively. Figure 4 shows the time course of changes in P,. There were no significant differences in baseline P, values among the three groups. P, in the orthodromic perfusion group increased significantly from 10.1 t 0.3 to 16.7 t 1.3 mmHg at 3 min after the antigen injection, followed by a gradual return toward the baseline level. In contrast, P, in the antidromic perfusion group decreased from the baseline values of 10.1 t 0.4 to 6.0 t 1.0 mmHg at 3 min after the antigen. P, in the control group did not change significantly from the baseline value throughout the experimental period. P, ,i tended to increase from 10.1 t 0.3 to Ascaris
suum
3 min
30 2.
Pulmonary Venous Pressure (mmHg)
30 2.
lo 0 E
6
r r
I.
L-L
F
Pulmonary Blood Flow (ml/min)
6oo
L'JW Weight
80
(g)
60
7;
‘-1
400 200 0
E
I
Pulmonary Venous Pressure
E
IO 0 2.
r
(mmHg)
0
Pulmonary Blood Flow
4oo 2oo 0
(mlimin)
,‘;
~---+I--~ Ut
10 t
E
60 Lung Weight (9)
40
20 Fig. 3. Representative recording of a response of lung weight, pulmonary arterial pressure, pulmonary venous pressure, and pulmonary blood flow to an injection of Ascaris suum antigen in antidromic perfusion
grOUP*
Figure 5 shows the time course of changes in Rt. R, in both the orthodromic perfusion and reverse-direction groups increased significantly at 3 min after the antigen injection and then gradually decreased toward the baseline level. Thereafter, Rt in the orthodromic perfusion group remained well above the baseline level throughout the experiment. In the antidromic perfusion group, Rt returned to the baseline level by 60 min after the antigen injection. No changes were observed in the control group throughout the experiment for 3 h. Additionally, changes in pulmonary Ra and R, are shown in Fig. 6. In both antigen-treated groups, Ra increased and reached a peak level 3 min after the antigen injection. However, these increased levels did not show significant differences between groups. In contrast, R, was increased significantly from 5.79 t 1.05 to 99.96 t
.AI' Y
Fig. 2. Representative recording of a response of lung weight, pulmonary arterial pressure, pulmonary venous pressure, and pulmonary blood flow to an injection of Ascaris suum antigen in orthodromic perfusion group*
(mmW
3 min
t
*O
12.6 t 1.1 mmHg at 60 min, but not significantly from the baseline value. P, i did not change significantly in either the antidromic’ perfusion group or the control
L:
I
lo 0
Pulmonary Arterial Pressure
suum
grOUP*
t Pulmonary Arterial Pressure (mmHg)
Ascaris
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(;i III
I
I
03
I
60 Time
I
I
120
12Or
I-1
Control
=
Anaphylaxis
w
Anaphylaxis
80-
g E 6
60-
E
20-
(min)
in control perfusion
*
3
60
0
Time
(min)
3
60
Fig. 6. Time course of pulmonary arterial (R,) and venous (R,) vascular perfusion (n = 5), and resistance in the control (n = 5), orthodromic antidromic perfusion (n = 5) groups. *P < 0.05 from baseline.
40-
A
OL
III
Q--Q---
h-
--&--&-Y-G&r--+:~
I
I 60 Time
03
1 120
180
(min)
Fig. 5. Time course of total pulmonary vascular resistance trol (n = 5)) orthodromic perfusion (n = 5)) and antidromic (n = 5) groups. *P < 0.05 from baseline.
(R,) in conperfusion
29.96 mmHg 1-l min 100 g in the orthodromic perfusion group and from 2.38 t 0.60 to 44.72 t 24.60 mmHg 1-l min 100 g in the antidromic perfusion group. Interestingly, R, of the baseline period in the antidromic perfused lungs was lower than that in the orthodromic perfused lungs. Figure 7 shows the time course of changes in KuC. There were no significant changes in &, in the control group. The lung weight of the orthodromic perfusion group showed a progressive increase within 40 min after the antigen injection. Thus KfC at 10 min after the injection was calculated by subtracting the weight gain just before the KfC determination. K,, in the orthodromic perfusion group tended to increase from 0.141 t 0.009 to 0.233 t 0.039 ml. min-l cmH,O-l 100 g-l at 10 min after the antigen injection. However, there were no significant changes in J& throughout the experiment. In the antidromic perfusion group, the lung weight showed a remarkable decrease after the antigen injection, followed by a recovery toward the baseline level within 60 min. In the antidromic perfusion group and the control group, there was no significant change in P& at any time interval of the data sampling during the experiment. The final-to-initial wet lung weight ratio in the control group was 1.37 t 0.07. The ratio of the orthodromic perfusion group was 1.74 t 0.06, which was significantly greater than that of the control group. But there was no l
l
(
Ra
J
0 f ,‘--I
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Fig. 4. Time course of isometric capillary pressure (P,,i) (n = 5), orthodromic perfusion (n = 5), and antidromic (n = 5) groups. *P < 0.05 from baseline. -
DOG
l
l
LI
l
l
I
0 IO
l
Fig. 7. Time course of capillary (n = 5), orth o d romic perfusion 5) groups.
I
60 Time
I
I
I
120 (min)
filtration coefficient (n = 5), and antidromic
1
180
(I&.) in control perfusion (n =
significant difference between the lung weight ratio of 1.48 t 0.11 in th e antidromic perfusion group and that of 1.37 & 0.07 in the control group. DISCUSSION
In the present study, we determined the pulmonary vascular responsesto anaphylaxis using the isolated lungs of dogs at a constant vascular and airway pressure. We have obtained two major findings in the present study. The first finding is that pulmonary microvascular pressure in dogs increases during anaphylaxis. This finding suggeststhat an increase in hydrostatic vascular pressure could contribute to an induction of pulmonary edema during anaphylactic shock. In addition, we observed a decrease in RJR, during increased pulmonary vascular resistance, indicating that pulmonary vasoconstriction due to anaphylaxis is attributed predominantly to pulmonary venoconstriction. This finding was subsequently reinforced and confirmed by the results of the antidromic perfusion group, the lungs of which were perfused in reversed direction from the pulmonary vein to artery. The
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second finding is that pulmonary vascular permeability, which was assessed by both pulmonary capillary filtration coefficient and pulmonary capillary filtration coefficient and pulmonary isogravimetric capillary pressure, does not change significantly between 1 and 3 h after anaphylaxis. Pulmonary anaphylaxis causes pulmonary vasoconstriction in various species of animals (4,6, 10, 13, 16,21) and in humans (25). However, changes in pulmonary capillary pressure, the determinant of pulmonary transvascular fluid filtration, has not been well evaluated in humans or in vivo animal experimental studies during pulmonary anaphylaxis. Selig et al. (21) showed, using isolated lungs of guinea pigs that were sensitized with ovalbumin, that antigen challenge produces immediate increases in pulmonary arterial pressure and lung weight. This finding is consistent with the present investigation. However, their observation (21) did not provide a cause of antigen-induced edema formation because of lack of measurements of either pulmonary capillary pressure or changes in vascular permeability. The present study provides evidence that an immediate increase in lung weight in response to the antigen is accompanied by an increase in pulmonary capillary pressure due to pulmonary venoconstriction. An increase in pulmonary capillary pressure due to venoconstriction could induce an increase in fluid movement from the intravascular space to the extravascular interstitium, resulting in lung water accumulation. It is interesting to point out that pulmonary venous pressure became lower when the pulmonary venous resistance increased. This finding shows dramatically why left atria1 pressure measurement in human lungs is not an appropriate measure of pulmonary capillary pressure. It is demonstrated that Ascaris suum antigen induces exclusively contraction of pulmonary vein of the canine lungs but not pulmonary artery. There are several explanations for the mechanism for the pulmonary venoconstriction seen in the present study. One possibility may be related to the location of the pulmonary vein; it is downstream of the pulmonary vessels in the longitudinal direction. If the anaphylactic reaction occurred predominantly in the lung parenchymal tissues, the pulmonary vein should be exposed to greater amounts of chemical mediators than the upstream side of the pulmonary artery. However, this possibility is unlikely, since the upstream side of pulmonary vasculature constricted predominantly in the reverse perfusion. As another possibility, mast cells, which are considered as responsible for the immunoglobulin E-type anaphylactic reactions, may distribute more densely around pulmonary veins than the pulmonary arteries. It has been reported that the density of mast cell in the lung was greater in parenchymal tissue than in the proximal airway (11). However, there are no reports available clarifying differences of the mast cell distribution in the vascular beds between pulmonary arteries and veins. The final and most likely possibility is that the pulmonary vein is more sensitive than the pulmonary artery to chemical mediators, which are released from the pulmonary tissues including mast cells in response to antigen challenge. Vasoactive substances such as histamine (20), thromboxane A2 (19), and leukotrienes C4 and D, (15) released by anaphylaxis preferentially constrict the pulmonary vein rather than the pulmonary ar-
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tery. In this respect, Kong and Stephens (13) have demonstrated the characteristic contractile response of the canine pulmonary vein to the antigens in isolated sensitized pulmonary vessels. They showed that anaphylaxis develops only on the pulmonary vein, but not on the pulmonary artery (13). In the present study, we found that venous resistance of baseline period in the antidromic perfusion is lower than that in the orthodromic perfusion. The reason for the lower venous resistance with venous perfusion as compared with arterial perfusion is uncertain. However, Barman and Taylor (1) showed in blood-perfused isolated dog lungs that segmental venous resistances decrease by ~50%, when venous pressure is raised to 15-20 cmH20. This finding is similar to our present studies in that pulmonary venous pressure elevation causes a decrease in segmental venous resistance even though the perfusion direction is opposite. The preferential vasodilation of the pulmonary vein in response to the increased vascular transmural pressure may account for these findings. It has been reported that pulmonary edema could occur in patients with anaphylactic shock (2, 5, 12, 18, 26), although the development of pulmonary edema is not uniformly observed in anaphylaxis. Furthermore, clinical investigations reported that this type of pulmonary edema develops within 1 h after exposure to the allergens such as hydrochlorothiazide (2, 5, 26) and diatrizoate sodium contrast medium for pyelogram (18). However, it remains unclear whether anaphylaxis-induced pulmonary edema is due to an increase in vascular permeability or an increase in vascular hydrostatic pressure. Carlson et al. (5) reported that the protein content of edema fluid from a patient with fulminant pulmonary edema during anaphylactic shock was rich compared with that of plasma, suggesting that pulmonary vascular permeability to proteins increased. In addition, Pemberton (18) also reported that plasmalike fluid was recovered from the airway of a patient with allergic reaction. On the other hand, experimental studies have failed to detect an increase in pulmonary microvascular permeability during pulmonary anaphylaxis. Pulmonary anaphylactic reaction in rats increased vascular permeability of the airway, but not of pulmonary parenchymal tissue (22). As demonstrated in the present study, the allergic reaction induced by Ascaris suum antigen does not produce any significant change in pulmonary microvascular permeability, which was evaluated by &, and P, i, for 3 h after the antigen injection. To determine changes in pulmonary microvascular permeability at the early stage of anaphylactic reaction, we measured J& at 10 min after administration of Ascaris suum. However, &c at 10 min was not conclusive for evaluating pulmonary vascular permeability because the lung just before the Kfc measurement was perfused at the zone 2 condition (PI < P,, < P,). The venous pressure value of -0.87 t 0.51 mmHg was smaller than the airway pressure of 3 cmH20, indicating that the pulmonary vascular surface area might not have been fully opened. In addition, pulmonary blood flow during Kfc measurement at 10 min was 0.35 t 0.06 1. min-l 100 g-! This could also have led to incomplete estimation of the vascular permeability because Kfc measured at low blood flow could underestimate the permeability changes of the l
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damaged lungs (23). However, even if an increase in vascular permeability might have occurred at an early phase of pulmonary anaphylaxis, we could suggest from the present finding that changes in the vascular permeability are transient and reversible, because no vascular permeability was found at 60 min or thereafter as evidenced by both absence of decreased P, i values and normal KfC values which were determined’effectively at zone 3 conditions and at the blood flow higher than one-half of baseline (23). The P, i of anaphylactic lungs remained higher than the baseline values and also greater than the corresponding values of either the control or antidromic perfusion groups. This could be attributable to an increase in pulmonary interstitial pressure secondary to an increase in extravascular lung water. The wet lung weight ratio in the orthodromic perfusion group was greatest among the three groups. The accumulation of the increased extravascular lung water may be accounted for by an increase in transvascular fluid filtration during pulmonary hypertension, which was seen at an early phase of anaphylactic reaction. In conclusion, canine pulmonary anaphylaxis induced by Ascaris suum antigen produced increases in pulmonary microvascular pressure and exclusively pulmonary venoconstriction. Any change in pulmonary microvascular permeability did not occur even with the existence of hemodynamic changes during the experimental period of 3 h. These results suggest that pulmonary edema accompanied by anaphylactic shock may be caused by an increase in hydrostatic pressure but not an increase in pulmonary vascular permeability. We are grateful to Dr. Steve Ammons for kindly reviewing this manuscript. This study was supported in part by Grant-in-Aid for Scientific Research 03454676 from the Ministry of Education, Science, and Culture of Japan and by a Grant-in-Aid for Pediatric Diseases from the Ministry of Health and Welfare of Japan. Address reprint requests to T. Shibamoto. Received
15 November
1991; accepted
in final
form
8 May
1992.
REFERENCES 1. Barman, S. A., and A. E. Taylor. Effect of pulmonary venous pressure elevation on vascular resistance and compliance. Am. J. Physiol. 258 (Heart Circ. Physiol. 27): Hll64-H1170, 1990. 2. Beaudry, C., and C. Laplante. Severe allergic pneumonitis from hydrochlorothiazide. Ann. Int. Med. 78: 251-253, 1973. 3. Bland, R. D., R. H. Demling, S. L. Selinger, and N. C. Staub. Effects of alveolar hypoxia on lung fluid and protein transport in unanesthetized sheep. Circ. Res. 40: 269-274, 1977. 4. Burka, J. F., T. R. DeLine, M. C. Holroyde, and P. Eyre. Chemical mediators of anaphylaxis (histamine, 5-HT, and SRS-A) released from horse lung and leukocytes in vitro. Res. Commun. Chem. Pathol. Pharmacol. 13: 379-388, 1976. 5. Carlson, R. W., R. C. Schaeffer, V. K. Puri, A. P. Brennan, and M. H. Weil. Hypovolemia and permeability pulmonary edema associated with anaphylaxis. Crit. Care Med. 9: 883-885, 1981. 6. Chand, N., and P. Eyre. Autacoid and anaphylactic reactivity of pulmonary and hepatic smooth musculature of the cat. Eur. J. Pharmacol. 45: 213-220, 1977. 7. Dawson, C. A., D. J. Grimm, and J. H. Linehan. Influence of hypoxia on the longitudinal distribution of pulmonary vascular
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resistance. J. Appl. Physiol. 44: 493-498, 1978. 8. Drake, R., K. A. Gaar, and A. E. Taylor. Estimation of the filtration coefficient of pulmonary exchange vessels. Am. J. Physiol. 234 (Heart Circ. Physiol. 3): H266-H274, 1978. 9. Essex, H. E. Anaphylactic and anaphylactoid reactions with special emphasis on the circulation. In: Handbook of Physiology. Circulation. Washington, DC: Am. Physiol. Sot., 1965, sect. 2, vol. 3, chapt. 66, p. 2301-2408. 10. Eyre, P. Pharmacology of bovine pulmonary vein anaphylaxis in vitro. Br. J. Pharmacol. 43: 302-311, 1971. 11. Gold, W. M., G. L. Meyers, D. S. Dain, R. L. Miller, and H. R. Bourne. Changes in airway mast cells and histamine caused by antigen aerosol in allergic dogs. J. Appl. Physiol. 43: 271-275, 1977. 12. James, L. P., and F. K. Austen. Fatal systemic anaphylaxis in man. N. Engl. J. Med. 270: 597-603, 1964. 13. Kong, S. K., and N. L. Stephens. Pharmacological studies of sensitized canine pulmonary blood vessels. J. Pharmacol. Exp. Ther. 219: 551-557, 1981. 14. Koyama, S., T. Fujita, H. Uematsu, T. Shibamoto, M. Aibiki, and S. Kojima. Inhibitory effect of renal nerve activity during canine anaphylactic hypotension. Am. J. Physiol. 258 (Regulatory Integrative Comp. Physiol. 27): R383-R387, 1990. 15. Noonan, T. C., W. M. Selig, D. F. Kern, and A. B. Malik. Mechanisms of peptidoleukotriene-induced increases in pulmonary transvascular fluid filtration. J. Appl. Physiol. 61: 1928-1934, 1986. 16. Ogunbiyi, P. O., and P. Eyre. Pharmacological studies of pulmonary anaphylaxis in vitro: a review. Agents Actions 17: 158-174, 1985. 17. Parker, J. C., M. I. Townsley, B. Rippe, A. E. Taylor, and J. Thigpen. Increased microvascular permeability in dog lungs due to high peak airway pressures. J. Appl. Physiol. 57: 1809-1816, 1984. 18. Pemberton, L. B. Shock lung with massive tracheal loss of plasma. J. Am. Med. Assoc. 237: 2511-2513, 1977. 19. Raj, J. U., and J. Anderson. Pulmonary venous response to thromboxane A2 analogue and atria1 natriuretic peptide in lambs. Circ. Res. 66: 496-502, 1990. 20. Rippe, B., J. C. Parker, M. I. Townsley, N. A. Mortillaro, and A. E. Taylor. Segmental vascular resistance and compliance in dog lung. J. Appl. Physiol. 62: 1206-1215, 1987. 21. Selig, W. M., A. M. Bendele, and J. H. Fleish. Antigeninduced edema formation, bronchoconstriction, and pulmonary vasospasm in the isolated perfused guinea pig lung: evidence for a secondary edematogenic response. Am. Rev. Respir. Dis. 138: 552559, 1988. 22. Sertl, K., M. L. Kowalski, J. Slater, and M. A. Kaliner. Passive sensitization and antigen challenge increases vascular permeability in rat airways. Am. Rev. Respir. Dis. 138: 1295-1299, 1988. 23. Shibamoto, T., J. C. Parker, A. E. Taylor, and M. I. Townsley. Derecruitment of filtration surface area in paraquatinjured isolated dog lungs. J. Appl. Physiol. 68: 1581-1589, 1990. 24. Shibamoto, T., A. E. Taylor, and J. C. Parker. PO, modulation of paraquat-induced microvascular injury in isolated dog lungs. J. Appl. Physiol. 68: 2119-2127, 1990. 25. Silverman, H. J., C. V. Hook, and E. F. Haponik. Hemodynamic changes in human anaphylaxis. Am. J. Med. 77: 341-344, 1984. 26 . Steinberg, A. D. Pulmonary edema following ingestion of hydrochlorothiazide. J. Am. Med. Assoc. 204: 825-827, 1968. A. E., and J. C. Parker. Pulmonary interstitial spaces 27. Taylor, and lymphatics. In: Handbook of Physiology. The Respiratory System. Circulation and Nonrespiratory Functions. Bethesda, MD: Am. Physiol. Sot., 1985, sect. 3, vol. 1, chapt. 4, p. 162-230. 28. Townsley, M. I., R. J. Korthuis, B. Rippe, J. C. Parker, and A. E. Taylor. Validation of double vascular occlusion method for PC,I in the lung and skeletal muscle. J. AppZ. Physiol. 61: 127-132, 1986.
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vascular response to anaphylaxis canine lungs
TOSHISHIGE YOSHIKAZU
SHIBAMOTO, TETSUYA HAYASHI, MATSUDA, MICHIKO KAWAMOTO,
JR., FUMITOSHI SAWANO, AND SHOZO KOYAMA
YUKA
SAEKI,
Department of Physiology, Division 2, Shinshu University School of Medicine, Matsumoto, Nagano 390, Japan Shibamoto, Toshishige, Tetsuya Hayashi, Jr., Fumitoshi Sawano, Yuka Saeki, Yoshikazu Matsuda, Michiko Kawamoto, and Shozo Koyama. Pulmonary vascular response to anaphylaxis in isolated canine lungs. Am. J. Physiol. 263 (Regulatory Integrative Comp. Physiol. 32): Rl024-R1029, 1992.-We determined changes in vascular resistance and microvascular permeability during anaphylactic reaction in isolated canine lungs perfused at constant pressure with autologous blood. In lungs with anaphylaxis induced by an intra-arterial injection of Ascaris suum antigen (10 mg), pulmonary vascular resistance and capillary pressure assessed as double occlusion pressure increased transiently by 10 times and 6.3 mmHg, respectively. Pre- to postcapillary vascular resistance ratio decreased from 0.89 ,t 0.05 to 0.21 t 0.06, suggesting predominant pulmonary venoconstriction. In lungs perfused in the antidromic direction from the pulmonary vein to the artery, anaphylaxis caused marked precapillary vasoconstriction, consistent with pulmonary venoconstriction. Vascular permeability assessed using the capillary filtration coefficient and isogravimetric capillary pressure did not change significantly for 3 h in either group. No changes were found in any variables in the saline-injected control lungs. The final weight of the anaphylactic lungs was significantly greater than that of the control lungs. Thus we conclude that anaphylaxis in isolated canine lung produces an increase in capillary pressure due to pulmonary venoconstriction without significant changes in vascular permeability. Pulmonary edema accompanied by anaphylactic hypotension may result from an increase in pulmonary hydrostatic intravascular pressure but not an increase in pulmonary vascular permeability. capillary filtration coefficient; pulmonary edema; pulmonary
isogravimetric capillary venoconstriction
pressure;
that pulmonary edema sometimes develops during anaphylactic shock (2, 5, 12, 18, 26). However, the exact mechanism responsible for the pathogenesis of anaphylaxis-induced pulmonary edema remains obscure. Pulmonary hypertension and increased pulmonary vascular resistance are found in anaphylactic shock of humans (25) and animals (9, 16). Various chemical mediators responsible for anaphylactic reaction could induce an increase in pulmonary arterial pressure (16). However, one of the most important determinants of pulmonary edema is an increase in pulmonary capillary pressure (27). Alveolar hypoxia causes pulmonary vasoconstriction. However, it does not affect lung fluid filtration because a site responsible for vasoconstriction is located in predominantly precapillary vessels (3, 7). However, it is not known whether pulmonary capillary pressure increases during anaphylaxisinduced pulmonary hypertension. With respect to changes in pulmonary microvascular permeability in the anaphylactic response, there are also no consistent concepts. Carlson et al. (5) reported that an increase in pulmonary vascular permeability was IT HAS BEEN KNOWN
observed in a patient with anaphylactic shock as based on the finding of increased protein concentration of the airway fluid compared with that of plasma. However, an increase in leakage of albumin was observed only in bronchial vessels but not pulmonary parenchymal vessels in experimental anaphylactic lungs of rats (22). Accordingly, it is not clear whether pulmonary edema associated with anaphylaxis is caused by an increase in hydrostatic pulmonary capillary pressure or an increase in pulmonary microvascular permeability. Therefore, the purpose of the present study was to determine if anaphylactic reaction induced by Ascaris suum antigen in the isolated blood-perfused canine lungs causes an increase in microvascular permeability and to define changes in the distribution of pulmonary vascular resistance of the lung with anaphylaxis. METHODS Isolated
Lung Preparation
Fifteen mongrel dogs (7-16 kg) were anesthetized with pentobarbital sodium (25 mg/kg iv). They were intubated and mechanically ventilated at a tidal volume of 15-20 ml/kg. The isolated lung preparation and perfusion system have been basically described (17, 23, 24). Catheters were placed in the left jugular vein and in the left carotid artery. Ten minutes after treatment with heparin sodium (500 U/kg iv) to avoid coagulation, the dog was rapidly bled through the carotid artery catheter. After left thoracotomy, the left lower lobe was excised near the hilum and was weighed. Plastic cannulas were secured in the pulmonary artery and vein and the lobar bronchus. Thereafter, perfusion was begun within 15 min after the excision of the lung. Lung Perfusion
System
Figure 1 shows a diagrammatic representation of the isolated lung perfusion system. The cannulated lobe was suspended from an electric balance (LF-600, Murakami Koki) and perfused at constant perfusion pressure with shed blood that was pumped from the outflow reservoir through a heat exchanger (37°C) into the inflow reservoir. Airway pressure was maintained at a constant level of 3 cmH,O. An overflow tube was connected to the inflow and outflow reservoirs to maintain a constant arterial perfusion pressure. The height of each reservoir could be adjusted independently to maintain arterial and venous pressures at any steady level. The perfused blood was oxygenated in the outflow reservoir by continuous bubbling with 95% 02-5% CO,. Pulmonary arterial (P,) and venous (P,) pressures were measured using pressure transducers that were placed on the reference points at the level of the hilum of the lung. Blood flow (&) was measured with an electromagnetic flowmeter (MFV 1200; Nihon Kohden, Tokyo, Japan), and the flow probe was positioned in the venous outflow line. Lung weight was continuously monitored and displayed on the physiograph. P, and P,
0363-6119/92 $2.00 Copyright 0 1992 the American Physiological Society R1024 Downloaded from www.physiology.org/journal/ajpregu by ${individualUser.givenNames} ${individualUser.surname} (129.215.017.190) on January 11, 2019.
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Preparation
AIR
ARTERIAL RESERVOIR I
HEAT
EXCHANGER
ROTARY PUMP
TR
Fig. 1. Diagram
of perfusion
of
Pulmonary
Vascular
Permeability
Capillary filtration coefficient. The capillary filtration coefficient (J&J was used as an index of microvascular permeability (8) and assessed by simultaneously increasing P, and P, by 6-8 mmHg from an isogravimetric state and observing the increase in weight of the lung. The sudden increase in vascular pressure caused a rapid weight gain of the lobe due to an increase in blood volume of the lung. This was followed by a gradual and prolonged weight gain that was attributed to transcapillary fluid filtration (8). The weight gain rate (dw/dt) at each minute following the increase in pressure (t = 0) was plotted as a semilogarithmic function with time, and the slow phase of the weight transient was extrapolated to time 0. When the lung was not isogravimetric but was gaining weight, this extrapolated rate of weight gain was subtracted by the weight gain rate 2 min just before Kf,, determination. The extrapolated rate of weight gain [ (dw/dt) t=o] was then divided by the increase in pulmonary capillary pressure (dP,). Capillary pressure (P,) was measured before and after the increase in vascular pressure using the double vascular occlusion technique (28). &c was normalized to the initial lung weight of 100 g to yield K,,, (in ml min-l cmH,O-l -100 g wet wt-‘) l
l
(0
dp C
Isogravimetric capillary pressure. The isogravimetric capillary pressure (P,:,,i) is the capillary pressure at which the lung neither gains nor loses weight. The prevailing pulmonary capillary pressure was measured using the double occlusion technique (28). The PC,; is determined by the following equation (2)
where 7rc and ri are plasma and interstitial protein oncotic pressures, respectively, Pi is interstitial pressure, and 0 is the capillary osmotic reflection coefficient for proteins. Thus PC,; can be used as an index of microvascular permeability of proteins if plasma protein concentration is constant. A decrease in P, i would indicate a decrease in vascular permeability to proteins because Pi tends to increase with increased filtration. The total vascular (R,), arterial (R,), and venous (R,) resistances were calculated as follows
The &to-R,
R, = (P, - p,>/&
(3
R, = (p, - q/Q
(4
R, = (PC - p,>/Q
(5
ratio (RJR,)
was also determined.
Ascaris
R1025
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suum Antigen
Protocol
Hemodynamic parameters of the perfused lung were observed for at least 20 min after the start of perfusion to reach an isogravimetric state at P, of 13-18 mmHg, P, of 2.5-4 mmHg, and a blood flow >0.7 liters mine1 100 g-l. All lobes with a baseline blood flow of ~0.7 liters min. 100 g-l were excluded from the present study. During baseline measurement, Kfc and P, i were determined twice, and the mean values were used as the baseline values. After these baseline measurements, all of the blood-perfused lobes were divided into the following three groups. Control group (n = 5). In these experiments, a 3-ml bolus of saline was injected into the arterial reservoir. Anaphylaxis group with orthodromic perfusion (n = 5). In these experiments, Ascaris suum antigen (10 mg) was diluted with 2 ml saline and was injected into the inflow arterial reservoir as a bolus. Anaphylaxis group with antidromic perfusion (n = 5). In these experiments, after the orthodromic perfusion of the isolated lung was established, the inflow tube was connected to the pulmonary vein and the outflow tube to the pulmonary artery. Thus the blood entered the lung lobe via the pulmonary vein and was withdrawn from the pulmonary artery. The same amount of Ascaris suum antigen as the orthodromic perfusion group was injected into the inflow (venous) reservoir. Kfc was measured at 10, 60, 120, and 180 min after the injection of the antigen or saline in each group. In the lobes that gained weight, vascular pressures were reduced to maintain the lobe in an isogravimetric state and to obtain P, i during the experimental period. However, in both orthodromic perfusion and antidromic perfusion groups, during the initial 30 min after the antigen challenge, the height of both reservoirs was not changed to observe the time course of the original responses. Then, the isogravimetric state was maintained until the end of the experiment. After the end of the experiment, the final weight of the perfused lung was measured, and the final wet weight-to-initial wet weight ratio was determined. l
l
l
Statistical P,i=Pi+a(~,-~i) 7
of
DOG
Ascaris antigen was prepared as previously described (14). Briefly, adult worms of Ascaris suum were triturated in saline and lyophilized. The material was resuspended in saline, further triturated by repeated freeze-pressing, and centrifuged. The supernatant was dialyzed against phosphate-buffered saline (pH 7.0), centrifuged, and stored at -20°C. Protein content was determined by micro-Kjeldahl. Ascaris suum antigen solution was adjusted with saline to obtain the protein concentration of 10 mg/ml. Experimental
system.
were initially adjusted to a level within the normal perfusion range in zone 3 (P, > P, > P,,, where P,, is airway pressure) and to obtain an isogravimetric state (no weight gain or loss). Measurements
IN ISOLATED
Analysis
All values are expressed as means k SE. Comparisons among all groups and within each group for a given variable were performed using analysis of variance followed by Duncan’s multiple-range test. P values 2.3 mmHg so as to keep the lung at zone 3 conditions. & decreased from the baseline value of 1.32 t 0.17 to 0.301 t 0.14 litersmin- L 100 g-l at 3 min after the
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Table 1. Pulmonary hemodynamics after anaphylaxis in isolated canine lungs Time
Hemodynamic Parameter
Group
n
After
Anaphylaxis,
min
Baseline
3
10
30
60
120
180
P,, cmHzO
Control 5 14.2t0.9 14.lkO.8 14.0t0.8 14.120.8 14.OkO.7 14.2t0.7 14.2t0.7 AI 5 15.8t0.7 20.4+l.l*Ji 20.6~1.0"~ 18.5+1.6*? 16.8tl.5 15.621.4 15.6tl.O &I 5 3.4t0.4 l.lt0.6* 1.6kO.5 2.6k0.4 2.9t0.3 2.8t0.2 2.9t0.3 P,, cmH20 Control 5 3.3kO.l 3.1k0.2 3.ltO.l 3.2tO.l 3.020.2 3.0tO.l 3.2t0.3 AI 5 3.0t0.4 -0.7+0.5*t -0.9+0.5*t 1.4+0.6*-t 2.7t0.3 2.3t0.4 2.620.3 &I 5 12.920.6 16.6t0.5* 15.7kO.7" 14.OkO.6 13.lt0.4 12.9t0.5 13.220.6 &, liter min-l 100 g-l Control 5 1.29t0.17 1.29kO.18 1.30t0.18 1.30t0.17 1.29t0.17 1.26t0.16 1.2lt0.16 AI 5 1.32t0.17 0.30+0.14*t 0.35+0.06*t 0.57+0.10*t 0.61+0.07*t 0.66kO.lO"t 0.62&0.10* AI1 5 1.33kO.13 0.59+0.18*-f 0.67+0.18*-f 1.13kO.15 1.18t0.19 1.20t0.20 1.15t0.20 Values are means t SE; n, no. of lobes. Control, control group; Ai, anaphylaxis group with orthodromic perfusion; An, anaphylaxis group with antidromic perfusion; P,, pulmonary arterial pressure; P,, pulmonary venous pressure; &, pulmonary blood flow. * P < 0.05 from baseline. t P < 0.05 vs. control group. l
l
antigen injection. There followed a recovery toward the preinjection level. In the antidromic perfusion group, changes in P, and P, were opposite to those of the orthodromic perfusion group, with an increase in P, and a decrease in Pa after the antigen challenge. & in this group decreased less than that in the orthodromic perfusion group. No significant changes in hemodynamic variables were found in the control group throughout the experimental period. Figures 2 and 3 show example recordings of responses to injection of Ascaris suum antigen from the orthodromic perfusion and antidromic perfusion groups, respectively. Figure 4 shows the time course of changes in P,. There were no significant differences in baseline P, values among the three groups. P, in the orthodromic perfusion group increased significantly from 10.1 t 0.3 to 16.7 t 1.3 mmHg at 3 min after the antigen injection, followed by a gradual return toward the baseline level. In contrast, P, in the antidromic perfusion group decreased from the baseline values of 10.1 t 0.4 to 6.0 t 1.0 mmHg at 3 min after the antigen. P, in the control group did not change significantly from the baseline value throughout the experimental period. P, ,i tended to increase from 10.1 t 0.3 to Ascaris
suum
3 min
30 2.
Pulmonary Venous Pressure (mmHg)
30 2.
lo 0 E
6
r r
I.
L-L
F
Pulmonary Blood Flow (ml/min)
6oo
L'JW Weight
80
(g)
60
7;
‘-1
400 200 0
E
I
Pulmonary Venous Pressure
E
IO 0 2.
r
(mmHg)
0
Pulmonary Blood Flow
4oo 2oo 0
(mlimin)
,‘;
~---+I--~ Ut
10 t
E
60 Lung Weight (9)
40
20 Fig. 3. Representative recording of a response of lung weight, pulmonary arterial pressure, pulmonary venous pressure, and pulmonary blood flow to an injection of Ascaris suum antigen in antidromic perfusion
grOUP*
Figure 5 shows the time course of changes in Rt. R, in both the orthodromic perfusion and reverse-direction groups increased significantly at 3 min after the antigen injection and then gradually decreased toward the baseline level. Thereafter, Rt in the orthodromic perfusion group remained well above the baseline level throughout the experiment. In the antidromic perfusion group, Rt returned to the baseline level by 60 min after the antigen injection. No changes were observed in the control group throughout the experiment for 3 h. Additionally, changes in pulmonary Ra and R, are shown in Fig. 6. In both antigen-treated groups, Ra increased and reached a peak level 3 min after the antigen injection. However, these increased levels did not show significant differences between groups. In contrast, R, was increased significantly from 5.79 t 1.05 to 99.96 t
.AI' Y
Fig. 2. Representative recording of a response of lung weight, pulmonary arterial pressure, pulmonary venous pressure, and pulmonary blood flow to an injection of Ascaris suum antigen in orthodromic perfusion group*
(mmW
3 min
t
*O
12.6 t 1.1 mmHg at 60 min, but not significantly from the baseline value. P, i did not change significantly in either the antidromic’ perfusion group or the control
L:
I
lo 0
Pulmonary Arterial Pressure
suum
grOUP*
t Pulmonary Arterial Pressure (mmHg)
Ascaris
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(;i III
I
I
03
I
60 Time
I
I
120
12Or
I-1
Control
=
Anaphylaxis
w
Anaphylaxis
80-
g E 6
60-
E
20-
(min)
in control perfusion
*
3
60
0
Time
(min)
3
60
Fig. 6. Time course of pulmonary arterial (R,) and venous (R,) vascular perfusion (n = 5), and resistance in the control (n = 5), orthodromic antidromic perfusion (n = 5) groups. *P < 0.05 from baseline.
40-
A
OL
III
Q--Q---
h-
--&--&-Y-G&r--+:~
I
I 60 Time
03
1 120
180
(min)
Fig. 5. Time course of total pulmonary vascular resistance trol (n = 5)) orthodromic perfusion (n = 5)) and antidromic (n = 5) groups. *P < 0.05 from baseline.
(R,) in conperfusion
29.96 mmHg 1-l min 100 g in the orthodromic perfusion group and from 2.38 t 0.60 to 44.72 t 24.60 mmHg 1-l min 100 g in the antidromic perfusion group. Interestingly, R, of the baseline period in the antidromic perfused lungs was lower than that in the orthodromic perfused lungs. Figure 7 shows the time course of changes in KuC. There were no significant changes in &, in the control group. The lung weight of the orthodromic perfusion group showed a progressive increase within 40 min after the antigen injection. Thus KfC at 10 min after the injection was calculated by subtracting the weight gain just before the KfC determination. K,, in the orthodromic perfusion group tended to increase from 0.141 t 0.009 to 0.233 t 0.039 ml. min-l cmH,O-l 100 g-l at 10 min after the antigen injection. However, there were no significant changes in J& throughout the experiment. In the antidromic perfusion group, the lung weight showed a remarkable decrease after the antigen injection, followed by a recovery toward the baseline level within 60 min. In the antidromic perfusion group and the control group, there was no significant change in P& at any time interval of the data sampling during the experiment. The final-to-initial wet lung weight ratio in the control group was 1.37 t 0.07. The ratio of the orthodromic perfusion group was 1.74 t 0.06, which was significantly greater than that of the control group. But there was no l
l
(
Ra
J
0 f ,‘--I
R1027
LUNG
180
Fig. 4. Time course of isometric capillary pressure (P,,i) (n = 5), orthodromic perfusion (n = 5), and antidromic (n = 5) groups. *P < 0.05 from baseline. -
DOG
l
l
LI
l
l
I
0 IO
l
Fig. 7. Time course of capillary (n = 5), orth o d romic perfusion 5) groups.
I
60 Time
I
I
I
120 (min)
filtration coefficient (n = 5), and antidromic
1
180
(I&.) in control perfusion (n =
significant difference between the lung weight ratio of 1.48 t 0.11 in th e antidromic perfusion group and that of 1.37 & 0.07 in the control group. DISCUSSION
In the present study, we determined the pulmonary vascular responsesto anaphylaxis using the isolated lungs of dogs at a constant vascular and airway pressure. We have obtained two major findings in the present study. The first finding is that pulmonary microvascular pressure in dogs increases during anaphylaxis. This finding suggeststhat an increase in hydrostatic vascular pressure could contribute to an induction of pulmonary edema during anaphylactic shock. In addition, we observed a decrease in RJR, during increased pulmonary vascular resistance, indicating that pulmonary vasoconstriction due to anaphylaxis is attributed predominantly to pulmonary venoconstriction. This finding was subsequently reinforced and confirmed by the results of the antidromic perfusion group, the lungs of which were perfused in reversed direction from the pulmonary vein to artery. The
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R1028
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second finding is that pulmonary vascular permeability, which was assessed by both pulmonary capillary filtration coefficient and pulmonary capillary filtration coefficient and pulmonary isogravimetric capillary pressure, does not change significantly between 1 and 3 h after anaphylaxis. Pulmonary anaphylaxis causes pulmonary vasoconstriction in various species of animals (4,6, 10, 13, 16,21) and in humans (25). However, changes in pulmonary capillary pressure, the determinant of pulmonary transvascular fluid filtration, has not been well evaluated in humans or in vivo animal experimental studies during pulmonary anaphylaxis. Selig et al. (21) showed, using isolated lungs of guinea pigs that were sensitized with ovalbumin, that antigen challenge produces immediate increases in pulmonary arterial pressure and lung weight. This finding is consistent with the present investigation. However, their observation (21) did not provide a cause of antigen-induced edema formation because of lack of measurements of either pulmonary capillary pressure or changes in vascular permeability. The present study provides evidence that an immediate increase in lung weight in response to the antigen is accompanied by an increase in pulmonary capillary pressure due to pulmonary venoconstriction. An increase in pulmonary capillary pressure due to venoconstriction could induce an increase in fluid movement from the intravascular space to the extravascular interstitium, resulting in lung water accumulation. It is interesting to point out that pulmonary venous pressure became lower when the pulmonary venous resistance increased. This finding shows dramatically why left atria1 pressure measurement in human lungs is not an appropriate measure of pulmonary capillary pressure. It is demonstrated that Ascaris suum antigen induces exclusively contraction of pulmonary vein of the canine lungs but not pulmonary artery. There are several explanations for the mechanism for the pulmonary venoconstriction seen in the present study. One possibility may be related to the location of the pulmonary vein; it is downstream of the pulmonary vessels in the longitudinal direction. If the anaphylactic reaction occurred predominantly in the lung parenchymal tissues, the pulmonary vein should be exposed to greater amounts of chemical mediators than the upstream side of the pulmonary artery. However, this possibility is unlikely, since the upstream side of pulmonary vasculature constricted predominantly in the reverse perfusion. As another possibility, mast cells, which are considered as responsible for the immunoglobulin E-type anaphylactic reactions, may distribute more densely around pulmonary veins than the pulmonary arteries. It has been reported that the density of mast cell in the lung was greater in parenchymal tissue than in the proximal airway (11). However, there are no reports available clarifying differences of the mast cell distribution in the vascular beds between pulmonary arteries and veins. The final and most likely possibility is that the pulmonary vein is more sensitive than the pulmonary artery to chemical mediators, which are released from the pulmonary tissues including mast cells in response to antigen challenge. Vasoactive substances such as histamine (20), thromboxane A2 (19), and leukotrienes C4 and D, (15) released by anaphylaxis preferentially constrict the pulmonary vein rather than the pulmonary ar-
IN ISOLATED
DOG
LUNG
tery. In this respect, Kong and Stephens (13) have demonstrated the characteristic contractile response of the canine pulmonary vein to the antigens in isolated sensitized pulmonary vessels. They showed that anaphylaxis develops only on the pulmonary vein, but not on the pulmonary artery (13). In the present study, we found that venous resistance of baseline period in the antidromic perfusion is lower than that in the orthodromic perfusion. The reason for the lower venous resistance with venous perfusion as compared with arterial perfusion is uncertain. However, Barman and Taylor (1) showed in blood-perfused isolated dog lungs that segmental venous resistances decrease by ~50%, when venous pressure is raised to 15-20 cmH20. This finding is similar to our present studies in that pulmonary venous pressure elevation causes a decrease in segmental venous resistance even though the perfusion direction is opposite. The preferential vasodilation of the pulmonary vein in response to the increased vascular transmural pressure may account for these findings. It has been reported that pulmonary edema could occur in patients with anaphylactic shock (2, 5, 12, 18, 26), although the development of pulmonary edema is not uniformly observed in anaphylaxis. Furthermore, clinical investigations reported that this type of pulmonary edema develops within 1 h after exposure to the allergens such as hydrochlorothiazide (2, 5, 26) and diatrizoate sodium contrast medium for pyelogram (18). However, it remains unclear whether anaphylaxis-induced pulmonary edema is due to an increase in vascular permeability or an increase in vascular hydrostatic pressure. Carlson et al. (5) reported that the protein content of edema fluid from a patient with fulminant pulmonary edema during anaphylactic shock was rich compared with that of plasma, suggesting that pulmonary vascular permeability to proteins increased. In addition, Pemberton (18) also reported that plasmalike fluid was recovered from the airway of a patient with allergic reaction. On the other hand, experimental studies have failed to detect an increase in pulmonary microvascular permeability during pulmonary anaphylaxis. Pulmonary anaphylactic reaction in rats increased vascular permeability of the airway, but not of pulmonary parenchymal tissue (22). As demonstrated in the present study, the allergic reaction induced by Ascaris suum antigen does not produce any significant change in pulmonary microvascular permeability, which was evaluated by &, and P, i, for 3 h after the antigen injection. To determine changes in pulmonary microvascular permeability at the early stage of anaphylactic reaction, we measured J& at 10 min after administration of Ascaris suum. However, &c at 10 min was not conclusive for evaluating pulmonary vascular permeability because the lung just before the Kfc measurement was perfused at the zone 2 condition (PI < P,, < P,). The venous pressure value of -0.87 t 0.51 mmHg was smaller than the airway pressure of 3 cmH20, indicating that the pulmonary vascular surface area might not have been fully opened. In addition, pulmonary blood flow during Kfc measurement at 10 min was 0.35 t 0.06 1. min-l 100 g-! This could also have led to incomplete estimation of the vascular permeability because Kfc measured at low blood flow could underestimate the permeability changes of the l
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VASCULAR
RESPONSE
TO ANAPHYLAXIS
damaged lungs (23). However, even if an increase in vascular permeability might have occurred at an early phase of pulmonary anaphylaxis, we could suggest from the present finding that changes in the vascular permeability are transient and reversible, because no vascular permeability was found at 60 min or thereafter as evidenced by both absence of decreased P, i values and normal KfC values which were determined’effectively at zone 3 conditions and at the blood flow higher than one-half of baseline (23). The P, i of anaphylactic lungs remained higher than the baseline values and also greater than the corresponding values of either the control or antidromic perfusion groups. This could be attributable to an increase in pulmonary interstitial pressure secondary to an increase in extravascular lung water. The wet lung weight ratio in the orthodromic perfusion group was greatest among the three groups. The accumulation of the increased extravascular lung water may be accounted for by an increase in transvascular fluid filtration during pulmonary hypertension, which was seen at an early phase of anaphylactic reaction. In conclusion, canine pulmonary anaphylaxis induced by Ascaris suum antigen produced increases in pulmonary microvascular pressure and exclusively pulmonary venoconstriction. Any change in pulmonary microvascular permeability did not occur even with the existence of hemodynamic changes during the experimental period of 3 h. These results suggest that pulmonary edema accompanied by anaphylactic shock may be caused by an increase in hydrostatic pressure but not an increase in pulmonary vascular permeability. We are grateful to Dr. Steve Ammons for kindly reviewing this manuscript. This study was supported in part by Grant-in-Aid for Scientific Research 03454676 from the Ministry of Education, Science, and Culture of Japan and by a Grant-in-Aid for Pediatric Diseases from the Ministry of Health and Welfare of Japan. Address reprint requests to T. Shibamoto. Received
15 November
1991; accepted
in final
form
8 May
1992.
REFERENCES 1. Barman, S. A., and A. E. Taylor. Effect of pulmonary venous pressure elevation on vascular resistance and compliance. Am. J. Physiol. 258 (Heart Circ. Physiol. 27): Hll64-H1170, 1990. 2. Beaudry, C., and C. Laplante. Severe allergic pneumonitis from hydrochlorothiazide. Ann. Int. Med. 78: 251-253, 1973. 3. Bland, R. D., R. H. Demling, S. L. Selinger, and N. C. Staub. Effects of alveolar hypoxia on lung fluid and protein transport in unanesthetized sheep. Circ. Res. 40: 269-274, 1977. 4. Burka, J. F., T. R. DeLine, M. C. Holroyde, and P. Eyre. Chemical mediators of anaphylaxis (histamine, 5-HT, and SRS-A) released from horse lung and leukocytes in vitro. Res. Commun. Chem. Pathol. Pharmacol. 13: 379-388, 1976. 5. Carlson, R. W., R. C. Schaeffer, V. K. Puri, A. P. Brennan, and M. H. Weil. Hypovolemia and permeability pulmonary edema associated with anaphylaxis. Crit. Care Med. 9: 883-885, 1981. 6. Chand, N., and P. Eyre. Autacoid and anaphylactic reactivity of pulmonary and hepatic smooth musculature of the cat. Eur. J. Pharmacol. 45: 213-220, 1977. 7. Dawson, C. A., D. J. Grimm, and J. H. Linehan. Influence of hypoxia on the longitudinal distribution of pulmonary vascular
IN ISOLATED
DOG
LUNG
R1029
resistance. J. Appl. Physiol. 44: 493-498, 1978. 8. Drake, R., K. A. Gaar, and A. E. Taylor. Estimation of the filtration coefficient of pulmonary exchange vessels. Am. J. Physiol. 234 (Heart Circ. Physiol. 3): H266-H274, 1978. 9. Essex, H. E. Anaphylactic and anaphylactoid reactions with special emphasis on the circulation. In: Handbook of Physiology. Circulation. Washington, DC: Am. Physiol. Sot., 1965, sect. 2, vol. 3, chapt. 66, p. 2301-2408. 10. Eyre, P. Pharmacology of bovine pulmonary vein anaphylaxis in vitro. Br. J. Pharmacol. 43: 302-311, 1971. 11. Gold, W. M., G. L. Meyers, D. S. Dain, R. L. Miller, and H. R. Bourne. Changes in airway mast cells and histamine caused by antigen aerosol in allergic dogs. J. Appl. Physiol. 43: 271-275, 1977. 12. James, L. P., and F. K. Austen. Fatal systemic anaphylaxis in man. N. Engl. J. Med. 270: 597-603, 1964. 13. Kong, S. K., and N. L. Stephens. Pharmacological studies of sensitized canine pulmonary blood vessels. J. Pharmacol. Exp. Ther. 219: 551-557, 1981. 14. Koyama, S., T. Fujita, H. Uematsu, T. Shibamoto, M. Aibiki, and S. Kojima. Inhibitory effect of renal nerve activity during canine anaphylactic hypotension. Am. J. Physiol. 258 (Regulatory Integrative Comp. Physiol. 27): R383-R387, 1990. 15. Noonan, T. C., W. M. Selig, D. F. Kern, and A. B. Malik. Mechanisms of peptidoleukotriene-induced increases in pulmonary transvascular fluid filtration. J. Appl. Physiol. 61: 1928-1934, 1986. 16. Ogunbiyi, P. O., and P. Eyre. Pharmacological studies of pulmonary anaphylaxis in vitro: a review. Agents Actions 17: 158-174, 1985. 17. Parker, J. C., M. I. Townsley, B. Rippe, A. E. Taylor, and J. Thigpen. Increased microvascular permeability in dog lungs due to high peak airway pressures. J. Appl. Physiol. 57: 1809-1816, 1984. 18. Pemberton, L. B. Shock lung with massive tracheal loss of plasma. J. Am. Med. Assoc. 237: 2511-2513, 1977. 19. Raj, J. U., and J. Anderson. Pulmonary venous response to thromboxane A2 analogue and atria1 natriuretic peptide in lambs. Circ. Res. 66: 496-502, 1990. 20. Rippe, B., J. C. Parker, M. I. Townsley, N. A. Mortillaro, and A. E. Taylor. Segmental vascular resistance and compliance in dog lung. J. Appl. Physiol. 62: 1206-1215, 1987. 21. Selig, W. M., A. M. Bendele, and J. H. Fleish. Antigeninduced edema formation, bronchoconstriction, and pulmonary vasospasm in the isolated perfused guinea pig lung: evidence for a secondary edematogenic response. Am. Rev. Respir. Dis. 138: 552559, 1988. 22. Sertl, K., M. L. Kowalski, J. Slater, and M. A. Kaliner. Passive sensitization and antigen challenge increases vascular permeability in rat airways. Am. Rev. Respir. Dis. 138: 1295-1299, 1988. 23. Shibamoto, T., J. C. Parker, A. E. Taylor, and M. I. Townsley. Derecruitment of filtration surface area in paraquatinjured isolated dog lungs. J. Appl. Physiol. 68: 1581-1589, 1990. 24. Shibamoto, T., A. E. Taylor, and J. C. Parker. PO, modulation of paraquat-induced microvascular injury in isolated dog lungs. J. Appl. Physiol. 68: 2119-2127, 1990. 25. Silverman, H. J., C. V. Hook, and E. F. Haponik. Hemodynamic changes in human anaphylaxis. Am. J. Med. 77: 341-344, 1984. 26 . Steinberg, A. D. Pulmonary edema following ingestion of hydrochlorothiazide. J. Am. Med. Assoc. 204: 825-827, 1968. A. E., and J. C. Parker. Pulmonary interstitial spaces 27. Taylor, and lymphatics. In: Handbook of Physiology. The Respiratory System. Circulation and Nonrespiratory Functions. Bethesda, MD: Am. Physiol. Sot., 1985, sect. 3, vol. 1, chapt. 4, p. 162-230. 28. Townsley, M. I., R. J. Korthuis, B. Rippe, J. C. Parker, and A. E. Taylor. Validation of double vascular occlusion method for PC,I in the lung and skeletal muscle. J. AppZ. Physiol. 61: 127-132, 1986.
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