Dopaminergic receptor regulates catecholamine release from perfused adrenal medulla

Nicotinic drug is a potent secretogogues for catecholamine from bovine adrenal glands perfused with oxygenated Locke's buffer. However, apomorphine, I IIM, [the dopaminergic agonist] markedly inhibit this catecholamine release by about 40%. Haloperidol 0.5 muM, [the dopaminergic antagonist] reversed the inhibitory effects of apomorphine. These data strongly suggested that, as in the cat, the bovine adrenal modulates the catecholamine cell contains a dopaminergic receptor that modulates the catecholamine secretory process triggered by stimulation of the nicotinic cholinergic receptor. This dopaminergic receptor might be involved in a sympathoadrenal cooperative mechanism