NEURONAL ION-CHANNEL SIGNALING PATHWAYS - MODULATION BY ANGIOTENSIN-II

The brain contains both angiotensin II (Ang II) type I (AT(1)) and Ang II type 2 (AT(2)) receptors. Neuronal AT(1) receptors mediate the sti mulatory actions of Ang II on blood pressure, water and salt intake, a nd secretion of vasopressin. In contrast, neuronal AT(1) receptors hav e been implicated in the stimulation of apoptosis and as being antagon istic to AT(1) receptors. The physiological actions of Ang II in the b rain, whether mediated by AT(1) or AT(2) receptors, involve changes in neuronal activity that are initiated by changes in the activity of me mbrane ionic currents and channels. This review focusses on the intrac ellular signalling pathways that couple neuronal AT(1) and AT(2) recep tors to changes in the activity of membrane K+ and Ca2+ currents and c hannels. As will become clear from our discussion, the signalling path ways that are modulated by neuronal AT(1) and AT(2) receptors are quit e distinct. (C) 1998 Elsevier Science Inc.