ABNORMALITIES OF WATER AND ELECTROLYTE METABOLISM IN RATS WITH HYPOTHALAMIC LESIONS

Abstract

In rats following bilateral lesions of the ventromedian region of the hypothalamus, the mean concn. of serum Na was significantly higher than in intact controls when food and water were freely available, and when both groups had been deprived of food and water for 16 hrs. When food alone was removed for 16 hrs., the difference in concn. of serum Na between the exptl. and control animals was not significant. Animals with lesions in the ventromedian region of the hypothalamus usually develop hyperphagia and obesity, and chronic disturbances of water metabolism. The present observations support the hypothesis that the delayed excretion of water loads and the increased renal tubular reabsorption of water shown by these animals reflect a chronic state of relative dehydration. The lower water /food intake ratios imply a deficit in the neural mechanism responsible for thirst and its alleviation[long dash]"hypothalamic hypodipsia.".