Renal Hypertrophy and Polydipsia in Potassium-Deficient Rats

Abstract

Young littermate male rats, usually about 4 weeks old, were pair-fed a control diet, or the same diet containing 0.3 m[image] K per 100 g. Most of the animals of both series were killed after 8 days or less at which time the animals on the K-deficient diet showed signs of K deficiency. In the deficient animals there was observed a reduction in muscle K, muscle chloride, and in plasma K, accompanied by an elevation of muscle sodium. Hypertrophy of the kidney, heart, and adrenals and involution of the thymus occurred in the K-deficient animals. K-deficient rats drank more water than did pair-fed controls. When deprived of water the deficient rats produced as coned, urine as did controls. Although a moderate water load was excreted equally effectively by rats of both groups, the maximal excretory capacity of the kidney was reduced in K-deficient animals. Renal hypertrophy was not prevented by lowering the Na/K ratio of the diet, by adrenalectomy, or by substitution of 0.9% saline for dist. drinking water. Polydipsia was enhanced by decreasing the Na content of the diet and diminished by the substitution of 0.9% saline for dist. drinking water. The relation of the hypophysis to renal hypertrophy, and possible causes of polydipsia were also discussed.