Action of N6(amido-3-propyl) adenosine hydrochloride (Agr 529) on plasma corticosterone levels in rats.

N6(amido-3-propyl) adenosine (Agr 529) has central properties analogous to those of adenosine. It increases plasma corticosterone levels in rats as a function of dose and of time. A plateau is reached at the dose of 10 mg.kg-1 one hour after intraperitoneal injection. Treatment with a blocker of adenosine receptors, 8-(p-sulfophenyl)-theophylline, which does not cross the blood-brain barrier, inhibits the increase of plasma corticosterone induced by Agr 529. This increase is also absent in hypophysectomized rats and in rats receiving Agr 529 intracerebroventricularly. Thus it is consistent to believe that Agr 529 increases plasma corticosterone in normal rats by acting on adenosine A2 receptors in the pituitary.