Histologic Alterations in the Adrenal Cortex of Intact and Hypophysectomized Rats Following ACTH, Pitressin and Adrenal Steroids

Intact and hypophysectomized rats were treated with DCA, cortisone, 9-alpha-fluorohydrocortisone, ACTH and Pitressin both singly and in various combinations. A histologic study was made of changes in the lipid content of the zones of the adrenal cortex in response to specific steroid treatment. DCA and cortisone caused lipid depletion from the zona glomerulosa and zona fasciculata, respectively, while 9-alpha-fluorohydrocortisone caused lipid depletion from both these zones. Pitressin, like DCA, caused lipid depletion from the zona glomerulosa of intact rats, but lipid storage in hypophysectomized rats. As treatment was extended (3–7 weeks), the hormonal effects on adrenal morphology appeared to be directly correlated with time. The zonal response to treatment was also related to the presence or the absence of the pituitary gland. Furthermore, these studies showed that the dose of ACTH is of particular importance in affecting good adrenal zonal maintenance and in offsetting the disuse atrophy induced by steroids. Also, the dose of ACTH must be increased to prevent zonal changes when more potent steroids, like 9-alpha-fluorohydrocortisone, are used.