Effect of atrial natriuretic peptide on the adenylate cyclase activity in the anterior and neurointermediate pituitary lobes of rats.

The effect of two atrial natriuretic peptides, rat ANP (3-28) and synthetic ANP (Arg101-Tyr126), on pituitary adenylate cyclase activity was measured in rats. Neither one was effective on basal, forskolin- or guanylylimidodiphosphate (GMP-PNP)-stimulated adenylate cyclase levels measured in homogenates of anterior and neurointermediate pituitary lobes. High concentrations (10(-7) and 10(-6) M) of ANPs further stimulate NaF-induced high adenylate cyclase activity - ANP (3-28) in both lobes, ANP (Arg101-Tyr126) only in the anterior lobe-but they were without effect in 10(-8) M or lower concentrations. These data indicate that ANP may not influence adenylate cyclase/cAMP system in the rat pituitary gland.