T-TYPE CALCIUM CHANNELS IN ADRENAL GLOMERULOSA CELLS - GTP-DEPENDENT MODULATION BY ANGIOTENSIN-II

With the use of whole-cell and single-channel current recordings, we h ave examined in more detail the site of action of angiotensin II (AII) on multiple populations of voltage-gated calcium channels in bovine a drenal glomerulosa cells. All (10 nM) enhances whole-cell T-type calci um channel current and increases the activity of single T-type calcium channels in cell-attached patch recordings. The AII-induced enhanceme nt of whole-cell calcium channel currents is dependent on the presence of internal GTP and can be inhibited by the competitive All-receptor antagonist saralasin (1 muM). These results show that AII augments the T-type calcium channel current in bovine adrenal glomerulosa cells.