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Brain ResearchBulletin,Vol. 25, pp. 1.5-17. Q Pergamon Press plc, 1990. Printed in the U.S.A.
Effect of Central Tachykinins, Alone and With Angiote~sin II, on Drinking in Pigs and Goats S. N. THORNTON’ ~epar~ent
AND B. A, BALDWIN
of ~e~vioura~ Physiology, A.F.R.C. Institute usAnimaL ~hysio~o~ and Genetics Research Cambridge Research Station, Babraham Hall, Cambridge CE.2 4AT, England Received 3 January
1990
THORNTON, S. N. AND B. A. BALDWIN. Efict of central tachykinins, alone and with angioten~i~ Il, an drinking in pigs and goats. BRAIN RES BULL 25(l) 15-17, 1990.--Central ad~nis~ation of the tachy~nins, eledoisin or physalaemin has been reported to produce significant water intake in pigeons but i~ibition of stimulateddrinking in rats. In this paper it is shown that high and low doses of these two tachykinins injected centrally in two much larger species, goats and pigs, did not produce any significant drinking. Furthermore, in pigs, physalaemin, but not eledoisin, attenuated AI1 stimulated drinking (576 -C64 ml AI1 alone, versus 456 + 131 ml AI1 + eledoisin, not significant, and 124 + 89 ml Al1 plus physalaemin, ~~0.01, in the same 5 pigs) and also, especially at the higher doses, induced general locomotor activation. However, in goats neither tachykinin interfered with drinking induced by central injection of 300 ng AIL These results show that in pigs and goats the tachykinins, eledoisin and physalaemin, are not effective dipsogens and that one of the possible reasons for the inhibitory action of physalaemin on AH-induced drinking may be through the general locomotor activation and not through a direct effect on the central AI1 system. Drinking
~~otensin
II
Goats
Eledoisin
of powdered food and concentrates (5050 mixture). Throughout the experiments the goats were housed in individual pens and fed a daily ration of hay and concentrates. Both groups of animals had ad lib access to water.
THE tachykinins, of which eledoisin and physalaemin are two examples, have been implicated in the central control of drinking in pigeons and in rats. Eledoisin (Ele) and physalaemin (Phys) injected into the cerebral ventricles (XV) are dipsogenic in pigeons (7,8) but antidipsogens in rats (3, 4, 8, 10, 12, 13); attenuating or i~ibiting drinking in response to central administration of angiotens~ II (AII) or carbachol, or in response to water deprivation or sodium loading. The response of other, larger, species to the tachykinins has been little studied, therefore, it was decided important to test these two tachykinins in pigs and goats, species in which large quantities of water are drunk in response to ICV injection of AI1 (1,15).
Surgery The animals were initially anaestbetised with halothane by face mask (pigs) or with an intravenous injection of methohexitone sodium (Brietal) (goats). Following endotracheal intubation, anaesthesia in both species was maintained with halothane via a closed circuit using a Boyle’s apparatus. Surgery was performed with sterile precautions and each animal was implanted with a stainless steel guide cannula directed towards the lateral cerebral ventricle [as described previously ( 1, 15)]. Cannula placement was subsequently verified by the ease with which 0.15 M NaCl ran into the ventricle under gravity and also by the drinking response to an ICV injection of 0.3 ml of 0.74 M NaCl.
METHOD
Twelve male pigs (Large-White, 20-30 kg) and six adult goats (of the Saanen breed, 60-70 kg) were used. The pigs were first trained to press a switch panel three times with their snouts to obtain 40-50 ml volume of water before being accustomed to living individually in modified metabolism cages where they stayed for the rest of the experiment. These cages were equipped with a switch panel and the pigs were fed twice daily with a ration
‘Requestsfor reprints should be addressed to Dr. S. N. Thornton, Marcelin-Berthelot,
Pigs
Experimental Procedure The pattern of drinking was recorded for 30 min following each ICV injection or pair of ICV injections. The test substances were injected in 0.3 ml and consisted of AI1 (Camb~dge Research
C.N.R.S.
75231 Paris Cedex 05, France.
15
lab. de Neurobiologie
des RCgulations,
Colltge
de France,
11
place
THORNTON AND BALDWIN
16
ICV Tachykinins in pigs
ICV Tachykinins in goats 2400
T
r T
1
2000 -I-
1600
1200
(6)
T
(12)
(7)
T
800
1a (5)
n
sal
All
Ele
Ele
300
800
1600
Ele
Phys
Phys
+
800
1600
All
400
C
Phys +
sal
All
Ele
Phys
PIG. 1. The volume of water drunk by pigs in 60 min in response to ICV administration of angiotensin II (AU, 300 ng), eledoisin (Ele, 800 and 1600 ng) and physalaemin (Phys, 800 and 1600 ng) alone and in combination. The control solution was 0.15 M NaCl (A). The number of pigs injected is given in parentheses. ***pO.O5). Physalaemin at both doses did not appear to produce a
significant drinking response, but it greatly reduced drinking in response to AII when both peptides were injected together. The volume of water drunk by the pigs in response to AII itself was significantly greater (p
Brain ResearchBulletin,Vol. 25, pp. 1.5-17. Q Pergamon Press plc, 1990. Printed in the U.S.A.
Effect of Central Tachykinins, Alone and With Angiote~sin II, on Drinking in Pigs and Goats S. N. THORNTON’ ~epar~ent
AND B. A, BALDWIN
of ~e~vioura~ Physiology, A.F.R.C. Institute usAnimaL ~hysio~o~ and Genetics Research Cambridge Research Station, Babraham Hall, Cambridge CE.2 4AT, England Received 3 January
1990
THORNTON, S. N. AND B. A. BALDWIN. Efict of central tachykinins, alone and with angioten~i~ Il, an drinking in pigs and goats. BRAIN RES BULL 25(l) 15-17, 1990.--Central ad~nis~ation of the tachy~nins, eledoisin or physalaemin has been reported to produce significant water intake in pigeons but i~ibition of stimulateddrinking in rats. In this paper it is shown that high and low doses of these two tachykinins injected centrally in two much larger species, goats and pigs, did not produce any significant drinking. Furthermore, in pigs, physalaemin, but not eledoisin, attenuated AI1 stimulated drinking (576 -C64 ml AI1 alone, versus 456 + 131 ml AI1 + eledoisin, not significant, and 124 + 89 ml Al1 plus physalaemin, ~~0.01, in the same 5 pigs) and also, especially at the higher doses, induced general locomotor activation. However, in goats neither tachykinin interfered with drinking induced by central injection of 300 ng AIL These results show that in pigs and goats the tachykinins, eledoisin and physalaemin, are not effective dipsogens and that one of the possible reasons for the inhibitory action of physalaemin on AH-induced drinking may be through the general locomotor activation and not through a direct effect on the central AI1 system. Drinking
~~otensin
II
Goats
Eledoisin
of powdered food and concentrates (5050 mixture). Throughout the experiments the goats were housed in individual pens and fed a daily ration of hay and concentrates. Both groups of animals had ad lib access to water.
THE tachykinins, of which eledoisin and physalaemin are two examples, have been implicated in the central control of drinking in pigeons and in rats. Eledoisin (Ele) and physalaemin (Phys) injected into the cerebral ventricles (XV) are dipsogenic in pigeons (7,8) but antidipsogens in rats (3, 4, 8, 10, 12, 13); attenuating or i~ibiting drinking in response to central administration of angiotens~ II (AII) or carbachol, or in response to water deprivation or sodium loading. The response of other, larger, species to the tachykinins has been little studied, therefore, it was decided important to test these two tachykinins in pigs and goats, species in which large quantities of water are drunk in response to ICV injection of AI1 (1,15).
Surgery The animals were initially anaestbetised with halothane by face mask (pigs) or with an intravenous injection of methohexitone sodium (Brietal) (goats). Following endotracheal intubation, anaesthesia in both species was maintained with halothane via a closed circuit using a Boyle’s apparatus. Surgery was performed with sterile precautions and each animal was implanted with a stainless steel guide cannula directed towards the lateral cerebral ventricle [as described previously ( 1, 15)]. Cannula placement was subsequently verified by the ease with which 0.15 M NaCl ran into the ventricle under gravity and also by the drinking response to an ICV injection of 0.3 ml of 0.74 M NaCl.
METHOD
Twelve male pigs (Large-White, 20-30 kg) and six adult goats (of the Saanen breed, 60-70 kg) were used. The pigs were first trained to press a switch panel three times with their snouts to obtain 40-50 ml volume of water before being accustomed to living individually in modified metabolism cages where they stayed for the rest of the experiment. These cages were equipped with a switch panel and the pigs were fed twice daily with a ration
‘Requestsfor reprints should be addressed to Dr. S. N. Thornton, Marcelin-Berthelot,
Pigs
Experimental Procedure The pattern of drinking was recorded for 30 min following each ICV injection or pair of ICV injections. The test substances were injected in 0.3 ml and consisted of AI1 (Camb~dge Research
C.N.R.S.
75231 Paris Cedex 05, France.
15
lab. de Neurobiologie
des RCgulations,
Colltge
de France,
11
place
THORNTON AND BALDWIN
16
ICV Tachykinins in pigs
ICV Tachykinins in goats 2400
T
r T
1
2000 -I-
1600
1200
(6)
T
(12)
(7)
T
800
1a (5)
n
sal
All
Ele
Ele
300
800
1600
Ele
Phys
Phys
+
800
1600
All
400
C
Phys +
sal
All
Ele
Phys
PIG. 1. The volume of water drunk by pigs in 60 min in response to ICV administration of angiotensin II (AU, 300 ng), eledoisin (Ele, 800 and 1600 ng) and physalaemin (Phys, 800 and 1600 ng) alone and in combination. The control solution was 0.15 M NaCl (A). The number of pigs injected is given in parentheses. ***pO.O5). Physalaemin at both doses did not appear to produce a
significant drinking response, but it greatly reduced drinking in response to AII when both peptides were injected together. The volume of water drunk by the pigs in response to AII itself was significantly greater (p
