Effects of Two Different Angiotensin II Antagonists on Aldosterone Secretion by Isolated Perfused Rat Zona Glomerulosa Cells*

Abstract

Isolated perfused rat zona glomerulosa cells have been used to determine the specificity of the angiotensin II antagonists, [Sar',Ala⁸]angiotensin II and [Sar',Ile⁸]angiotensin II. Both antagonists inhibited the aldosterone response to angiotensin II but did not affect serotonin- or potassium-induced aldosterone secretion. However, in contrast to [Sar1,Ala8]angiotensin II, [Sar1,Ile8]angiotensin II inhibited the aldosterone response to ACTH. These results suggest that there are differences in the specificity of these two analogs and that studies with [Sar',Ile⁸]angiotensin II and its effect on aldosterone secretion should be interpreted with caution.