Abstract: | Secretion of cortisol is under stimulatory regulation by ACTH, and cortisol secreted, in turn, inhibits ACTH secretion by the pituitary. Therefore, measurement of plasma ACTH is indispensable in the diagnosis of the adrenocortical diseases. The adrenal cortex is included in the hypothalamo-adenohypophysial-adrenocortical system, and the pathogenesis of these disorders must be evaluated. An interaction between the hypothalamo-adenohypophysial-adrenal system and the immune system have been suggested. We studied the effect of interleukin-1 (IL-1) on ACTH secretion by cultured rat pituitary cells in vitro. Our results suggest that IL-1 stimulates the ACTH secretion by enhancing its synthesis by the pituitary, rather than ACTH release. |