Formation of DES-ASP1-angiotensin II is not an obligatory step in the steroidogenic action of angiotensin II in the canine adrenal.

A comparison of the receptor binding properties and in vitro metabolism of angiotensin II and [des-Asp1]-angiotensin II was performed in collagenase-dispersed glomerulosa cells from dog adrenal glands. Each peptide was bound rapidly and reversibly to isolated glomerulosa cells, with similar equilibrium and kinetic constants of association and dissociation. The labeled peptide that was bound to glomerulosa cells after incubation with 125I- and 3H-angiotensin II at 37C for 30-60 minutes was predominantly angiotensin II, with about 15% [des-Asp1]-angiotensin II. These findings demonstrate that local formation of the heptapeptide is not an obligatory step in the action of angiotensin II on aldosterone production in the canine adrenals.