1038 PROSTAGLANDINS AND RENIN IN
in all,
belonged to community-type I (i.e., generally less urban municipalities in which the service trades employ most people)
SCHIZOPHRENIA
SiR,—Ibelieve that Dr Horrobin’s hypothesis (April 30, p.
936)-that schizophrenia may be a prostaglandin-deficiency supported by findings in experiments involving the renin-angiotensin system. Prostaglandins are probably important in controlling renal vasculature and, possibly, systemic blood-pressure. Prostaglandin inhibitors produced a gradual rise in renal vascular resistance in the in-situ feline kidney. Furthermore, this rise was attenuated by an angiotensin-n antagonist. Kotchen and Miller3 demonstrated that prostaglandins are competitive inhibitors of renin. Other groups’·’ found that prostaglandin depletion, induced by a diet deficient in arachidonic acid, increased the rate at which hypertension developed in rats receiving a high-salt intake; whereas administration of arachidonic acid to spontaneously hypertensive rats reduced their blood-pressure. These data show a definite inverse relation between prostaglandins and the activity of the renin-angiotensin system. Consequently, I spot-checked the blood-renin concentrations in three young untreated paranoid schizophrenics who were on a normal salt diet. All three were physically normal. Blood-renin in the upright positions were 2.5, 3.3, and 7-55 ng/ml. The comparable mean normal values in our laboradisease-is
tory are 2-0±0-5 S.D. ng/ml. In view of the relation between renin and prostaglandin activity, the relatively high renin concentrations in these patients may be the result of prostaglandin
deficiency. Department of Internal Medicine, Hadassah University Hospital, Mount Scopus, Jerusalem, Israel
Y. LITVIN
and the remainder, with 208 000 inhabitants, were more urban with most people working in industry (type n). Of the ten hard-water municipalities seven (112 000 inhabitants) were type i and three (150 000 inhabitants) were type n. The means of the municipal, age-adjusted cardiovascular (I.C.D. 39058) mortality-rates for males and females in the period 1969-72 were computed for the two municipality groups with soft and hard water and their community-type subgroups (see table). The table seems to tell the familiar "water story"-namely, that cardiovascular mortality decreases, irrespective of community type and sex, with increasing water hardness. The cardiovascular mortality rate for the ten hard water-municipalities (mean average hardness 3.10) was 5-10% lower for both sexes than in the forty soft-water municipalities (mean average hardness 1 0°). EYSTEIN GLATTRE Institute of Hygiene, ROLF ASKEVOLD University of Oslo, Oslo 3, Norway IDA GOFFENG BAY ELISA FOR HERPES SIMPLEX VIRUS TYPE 2 ANTIBODIES
SiR,—The seroepidemiology of herpes simplex virus
(H.S.V.) type 2 infection in man has been hampered by difficulties in demonstrating antibodies specific for H.S.v. type 2 in sera with cross-reacting H.s.v. type 1 antibodies.’ Methods available are based on the relative proportions of antibody reactivity against both H.s.v. types2 or on elaborate absorption procedures to remove cross-reacting H.s.v. antibodies before
testing.3
We describe here a simple routine test for the titration of type 2 specific antibodies in human sera by ELISA (enzyme-linked immunosorbent assay) using H.S.V. type 2 specific antigen obtained by immunoabsorption. H.s.v. membrane-bound glycoproteins obtained from infected rabbit cornea cells solubilised with ’Triton X-100’were H.s.v.
NORWEGIAN WATER STORY
SIR,-Water collected in 1972 for another purpose from all the 290
registered water supplies in the Oslofjord area (comprising seventy-six municipalities and 1 700 000 people) has been tested for calcium (Ca) and magnesium (Mg). From the Ca and Mg content of each sample, measured in German hardness degrees (1 equivalent to 7.15 mg/1 Ca or 4.334 mg/1 Mg), and the number of people on each water supply, a weighted MEAN MUNICIPAL
AGE-ADJUSTED RATES PER
CARDIOVASCULAR MORTALITY
100 000
purified by ion-exchange chromatography.4 H.S.v. polyspecific antigen was prepared from type 1 (strain F) infected cells and control antigen from non-infected cells. H.s.v. type 2 specific antigen was prepared from type 2 (strain G) infected cells by passing the chromatographically purified glycoproteins through a cyanogen-bromide-activated ’Sepharose 4B’ column coupled previously with polyspecific anti-H.s.v. type 1 purified rabbit
immunoglobulin.s
The fractions obtained from the im-
SUMMAItY OF ELISA OPTICAL-DENSITY VALUES
Values as mean (and range).
average of
water hardness was computed for each municipafifty municipalities where 60% or more of the inhabitants got their water from registered water supplies were selected for further analysis. The selected municipalities were divided into two groupsforty with water hardness less than I - 75and ten with municipal, average water hardness 1-73°or more. Of the soft-water (
in all,
belonged to community-type I (i.e., generally less urban municipalities in which the service trades employ most people)
SCHIZOPHRENIA
SiR,—Ibelieve that Dr Horrobin’s hypothesis (April 30, p.
936)-that schizophrenia may be a prostaglandin-deficiency supported by findings in experiments involving the renin-angiotensin system. Prostaglandins are probably important in controlling renal vasculature and, possibly, systemic blood-pressure. Prostaglandin inhibitors produced a gradual rise in renal vascular resistance in the in-situ feline kidney. Furthermore, this rise was attenuated by an angiotensin-n antagonist. Kotchen and Miller3 demonstrated that prostaglandins are competitive inhibitors of renin. Other groups’·’ found that prostaglandin depletion, induced by a diet deficient in arachidonic acid, increased the rate at which hypertension developed in rats receiving a high-salt intake; whereas administration of arachidonic acid to spontaneously hypertensive rats reduced their blood-pressure. These data show a definite inverse relation between prostaglandins and the activity of the renin-angiotensin system. Consequently, I spot-checked the blood-renin concentrations in three young untreated paranoid schizophrenics who were on a normal salt diet. All three were physically normal. Blood-renin in the upright positions were 2.5, 3.3, and 7-55 ng/ml. The comparable mean normal values in our laboradisease-is
tory are 2-0±0-5 S.D. ng/ml. In view of the relation between renin and prostaglandin activity, the relatively high renin concentrations in these patients may be the result of prostaglandin
deficiency. Department of Internal Medicine, Hadassah University Hospital, Mount Scopus, Jerusalem, Israel
Y. LITVIN
and the remainder, with 208 000 inhabitants, were more urban with most people working in industry (type n). Of the ten hard-water municipalities seven (112 000 inhabitants) were type i and three (150 000 inhabitants) were type n. The means of the municipal, age-adjusted cardiovascular (I.C.D. 39058) mortality-rates for males and females in the period 1969-72 were computed for the two municipality groups with soft and hard water and their community-type subgroups (see table). The table seems to tell the familiar "water story"-namely, that cardiovascular mortality decreases, irrespective of community type and sex, with increasing water hardness. The cardiovascular mortality rate for the ten hard water-municipalities (mean average hardness 3.10) was 5-10% lower for both sexes than in the forty soft-water municipalities (mean average hardness 1 0°). EYSTEIN GLATTRE Institute of Hygiene, ROLF ASKEVOLD University of Oslo, Oslo 3, Norway IDA GOFFENG BAY ELISA FOR HERPES SIMPLEX VIRUS TYPE 2 ANTIBODIES
SiR,—The seroepidemiology of herpes simplex virus
(H.S.V.) type 2 infection in man has been hampered by difficulties in demonstrating antibodies specific for H.S.v. type 2 in sera with cross-reacting H.s.v. type 1 antibodies.’ Methods available are based on the relative proportions of antibody reactivity against both H.s.v. types2 or on elaborate absorption procedures to remove cross-reacting H.s.v. antibodies before
testing.3
We describe here a simple routine test for the titration of type 2 specific antibodies in human sera by ELISA (enzyme-linked immunosorbent assay) using H.S.V. type 2 specific antigen obtained by immunoabsorption. H.s.v. membrane-bound glycoproteins obtained from infected rabbit cornea cells solubilised with ’Triton X-100’were H.s.v.
NORWEGIAN WATER STORY
SIR,-Water collected in 1972 for another purpose from all the 290
registered water supplies in the Oslofjord area (comprising seventy-six municipalities and 1 700 000 people) has been tested for calcium (Ca) and magnesium (Mg). From the Ca and Mg content of each sample, measured in German hardness degrees (1 equivalent to 7.15 mg/1 Ca or 4.334 mg/1 Mg), and the number of people on each water supply, a weighted MEAN MUNICIPAL
AGE-ADJUSTED RATES PER
CARDIOVASCULAR MORTALITY
100 000
purified by ion-exchange chromatography.4 H.S.v. polyspecific antigen was prepared from type 1 (strain F) infected cells and control antigen from non-infected cells. H.s.v. type 2 specific antigen was prepared from type 2 (strain G) infected cells by passing the chromatographically purified glycoproteins through a cyanogen-bromide-activated ’Sepharose 4B’ column coupled previously with polyspecific anti-H.s.v. type 1 purified rabbit
immunoglobulin.s
The fractions obtained from the im-
SUMMAItY OF ELISA OPTICAL-DENSITY VALUES
Values as mean (and range).
average of
water hardness was computed for each municipafifty municipalities where 60% or more of the inhabitants got their water from registered water supplies were selected for further analysis. The selected municipalities were divided into two groupsforty with water hardness less than I - 75and ten with municipal, average water hardness 1-73°or more. Of the soft-water (
