Hypertension of Renal Origin in Rats Following Choline Deficiency

The production of arterial hypertension by dietary defi- ciency alone has not previously been demonstrated.Since the report by Griffith and Wade (1939) it has been well established that choline deficiency produces severe renal lesions in young rats (Gyorgy and Goldblatt, 1940; Engel and Salmon, 1941 ; Handler, 1946; and others).A careful study of the blood pressures of rats maintained for long periods on diets low in choline has been made by Sobin and Landis (1947), who found no evidence of hypertension.The results of earlier studies by Honorato and Vadillo (1944) apparently support this same conclusion.Stimulated in part by these papers, by discussions with Professor Eugene Landis, and by the early studies of choline defi- ciency in our laboratories (Best and Huntsman, 1932), we decided to produce a severe renal lesion by this dietary means and then to study the blood pressures of the sur- viving animals maintained on full diets.Under these con- ditions, in our present series of observations all animals with severe residual renal damage developed hypertension.The average figure for ten animals in this group was 195 mm.Hg.This is the mean pressure recorded by arterial cannulation.The comparable figure for 36 control animals was 118 mm.Hg. MethodsWeanling albino rats of the Wistar strain weighing 35-42 g. were fed a diet low in choline (T45) as described by our colleagues Lucas and Ridout (1948).The obrjet was to produce the greatest degree of renal damage com- patible with life.The animals were fed the choline- deficient diets for varying lengths of time.Most of the rats received the ration for five to six days.In the more recent experiments the animals were fed the choline- deficient diet for four five-day periods separated by two- day intervals during which the diet was supplemented with 0.35% choline chloride.All the animals received a stock diet for the remainder of the experiment.In the early studies the rats were sacrificed at the age of 3 to 4 months, but it was subsequently discovered that a higher percentage developed hypertension if allowed to live for six or seven months.Control animals were pair-fed with those receiving the choline-deficient diet.These controls received the T45 diet supplemented with 0.35% choline chloride.They were given the stock diet ad libitum at the same time as the *These histological studies were aided by a grant from the National Research Council of Canada, 1948, and the nutritional aspects of the work were financed in part by the Nutrition Foundation in New York.