Role of MAPKs in angiotensin II-induced steroidogenesis in rat glomerulosa cells.

Angiotensin II is one of the most important stimuli of rat adrenal glomerulosa cells, stimulating both steroid secretion and growth. In a previous report, we had shown that Ang II promotes cellular hypertrophy, but not proliferation, in rat adrenal glomerulosa cells maintained in primary culture for 3 days. The inhibition of proliferation and stimulation of hypertrophy induced by Ang II involves both p42/p44(mapk) and p38 MAPK activation. The increase in cell protein content induced by Ang II entails formation of a cortical actin ring and Rac-dependent activation of p42/p44(mapk) and p38 MAPK. The present study summarizes these results and provides evidences that Ang II-induced activation of p42/p44(mapk) and p38 MAPK are implicated in aldosterone secretion by enhancing expression of specific steroidogenic proteins such as StAR and 3beta-HSD.