Water Balance in Adrenal Insufficiency and Inanition. ∗

Abstract

Recent reports of water balance studies during adrenal insufficiency in the dog 1 , 2 , 3 indicate that in that animal urine volumes, following cessation of cortin injections in adrenalectomized animals, are maintained at or above normal levels in spite of lowered water intake, with little or no reduction until shortly before death. Harrop, et al. 2 attribute the hemoconcentration which occurs during adrenal insufficiency to loss of fluid by way of the kidneys, and Swingle, et al. 3 also regard such loss as an important factor in reduction of plasma volume, though not the sole one.

The experiments herein reported were undertaken to ascertain whether similar results could be obtained with the cat, and whether any changes in water balance could be specifically referred to adrenal insufficiency.

Seven cats were used in these experiments; 3 of them were adrenalectomized and were on a maintenance dosage of cortin before experiments began; the other 4 had one adrenal out in the beginning, and the second adrenal was removed during the course of the investigation. One cat was followed not only during 2 such periods of adrenal insufficiency, but also during one period of recovery following cortin deficiency. Two cats were used during periods of gradual reduction of food intake simulating the reduction which occurs in the development of adrenal insufficiency, then a period of increasing food intake simulating recovery from insufficiency; finally the one remaining adrenal was removed and the same animals studied during the development of cortical insufficiency.

The water intake in food and drink was measured, and the metabolic water calculated. The water output in urine and feces was measured, and in addition a rough estimate of the insensible loss was made from the data on intake and output and the daily weight changes of the animal.