Epinephrine and Norepinephrine Stimulation of Adenylate Cyclase in Bovine Retina Homogenate: Evidence for Interaction with the Dopamine D1 Receptor

Dopamine, epinephrine and norepinephrine provoke dose-dependent stimulation of adenylate cyclase activity in bovine retina homogenates. The stimulatory effect of all three compounds is inhibited by the D1 antagonist SCH 23390 and, in a stereoselective manner by the cis-isomer of flupenthixol. The D2 antagonist haloperidol and alpha-and beta-adrenergic antagonists failed to block the catecholamine stimulation. These results evidence that, in bovine retina, not only dopamine but also epinephrine and norepinephrine interact with dopamine D1 receptors that are stimulatory coupled to an adenylate cyclase system.