PEPTIDE GROWTH-FACTORS AND THE ADRENAL-CORTEX

Increasing evidence suggests that the actions of classical stimulants of adrenocortical growth and function, such as ACTH or dietary sodium restriction, may partially be mediated via locally produced regulators . Several peptide growth factors, such as basic fibroblast growth fact or, insulin-like growth factors, and transforming growth factor-beta(1 ), have emerged in recent years as multifunctional molecules that typi cally play such regulatory roles. Adrenocortical cells are highly resp onsive to these growth factors, in particular in the regulation of cel l growth and differentiated functions, such as steroidogenesis. In add ition, growth factor expression in the adrenal cortex has been shown t o be regulated by physiological stimulants. The spatial expression, re lease, and activation of these growth factors may, therefore, locally mediate or amplify the actions of the hypothalamo-pituitary axis and t he renin-angiotensin system on adrenocortical proliferation, different iation, and steroidogenesis. (C) 1997 Wiley-Liss, Inc.