The growth-promoting effects of angiotensin II in adrenal glomerulosa cells: An interactive tale

The zona glomerulosa of the adrenal cortex is well-known for its high level of proliferation, compared to the adjacent zona fasciculata, both in in vivo and in vitro conditions. Angiotensin II (Ang II) is a potent growth factor for glomerulosa cells, appearing as a proliferative factor in vivo, under sodium-deficient diet conditions, as well as in vitro, in studies conducted with whole zona glomerulosa. However, in cells maintained in primary culture for 3 days, Ang II rather promotes cellular hypertrophy with a concomitant arrest in basal cell proliferation. The present essay aims at providing experimental arguments supporting such unexpected observations, with particular focus on the modulatory impact of the extracellular environment on Ang II action, namely AT1 receptor-induced signaling pathways and cell responses.