Abstract
Excretion of a combined load of water and inulin is significantly delayed in rats suffering from lack of either pantothenic acid, pyridoxine and riboflavin. In view of the fact that treatment of the deficient animals with either ACTH or cortisone increased the excretion of both water and inulin, in contrast to normal control rats, it is concluded that the depressed glomerular filtration rate of these two substances is due to an adrenal insufficiency. In rats suffering from either protein or choline deficiency, as well as in normal rats treated with Pitressin, the excretion of inulin remains normal, whereas the water diuresis is delayed. These results, confirming previous findings, would appear to indicate an impaired hepatic inactivation of the posterior pituitary hormone in these nutritional deficiencies. Thiamine deficient rats also exhibit a delayed diuretic response to a combined inulin-water load, which cannot, however, completely be restored to normal by ACTH or cortisone.