EXTRARENAL ASPECTS OF ANGIOTENSIN-II FUNCTION

The cloning of angiotensin II (Ang II) receptor genes and the availabi lity of specific receptor ligands allows characterization of,lng II re ceptor-mediated actions, Most of the well-known Ang II effects such as vasoconstriction. drinking response and cell proliferation are mediat ed through the AT(1) receptor. Little is known about the physiological effect of the AT(2) receptor, though there are some reports describin g the involvement of the AT(2) receptor in blood pressure regulation. Recent data demonstrate that the AT(2)-mediated actions are inhibitory to AT(2)- and mitogen-induced growth effects, indicating a balancing mechanism for Ang II-controlled mechanisms. It has also been demonstra ted that AT(2) receptor inactivation induces endothelial cell prolifer ation in the presence of Ang II. Additionally! AT(2) receptor activati on enhances nerve growth factor-induced differentiation of PC12W cells and a role in apoptotic changes has also been reported. Based on rece nt findings, this article focuses on the role of Ang II in growth and differentiation processes with respect to the AT(2) receptor in these events.