Role of the Kidney in Adrenocortical Response to Hemorrhage in Hypophysectomized Dogs

The role of the kidney in the regulation of aldosterone secretion has been investigated by determining the effect of nephrectomy on aldosterone secretion before and after hemorrhage in hypophysectomized dogs, and the effect of the injection of saline extracts of kidney and spleen on aldosterone secretion in nephrectomized hypophysectomized dogs. Nephrectomy led to a significant decrease in aldosterone secretion in hypophysectomized dogs and in 8 of 10 dogs, prevented the rise that followed hemorrhage in the control hypophysectomized dogs with intact kidneys. Saline extracts of kidneys caused a 10-fold or greater rise in aldosterone secretion and a small, submaximal increase in 17-hydroxycorticoid and corticosterone secretion. Isotonic saline and saline extracts of spleen had no significant effect on adrenocortical secretion. One iu doses of commercial ACTH increased aldosterone secretion, but caused maximal 17-hydroxycorticoid and corticosterone secretion. Small doses of ACTH produced increments in 17-hydroxycorticoids comparable to those observed in hypophysectomized dogs with intact kidneys. These findings are consistent with the hypothesis that a renal mechanism, probably the renin-angiotensin system, is mainly responsible for the increase in aldosterone secretion following hemorrhage in hypophysectomized dogs.