Veratridine, angiotensin receptors and aldosteronogenesis in bovine adrenal glomerulosa cells.

Veratridine inhibited angiotensin binding to its receptors in bovine adrenal glomerulosa cells and vascular smooth muscle. Fifty percent inhibition of adrenal receptors required about 2 X 10(-5) M veratridine. Receptors from vascular tissue were less sensitive. Graphic analysis showed that inhibition resulted primarily from a reduction of receptor number. Angiotensin stimulation of phosphatidylinositol turnover and of aldosterone production was inhibited by veratridine. Analogues of veratridine varied in their receptor inhibitory potency, but these variations did not correlate with the potencies of analogues as hypotensive agents or inhibitors of aldosteronogenesis. Very low extracellular sodium concentrations inhibited the adrenal effects of angiotensin. Neither veratridine nor grayanotoxin, both of which open sodium channels in excitable tissues, had a detectable effect on sodium fluxes in adrenal cells. Inhibition of aldosteronogenesis by veratridine is more likely the result of receptor and post-receptor effects than an alteration of the sodium channel.