Sims_1988_Science_239_190

The beta-adrenergic agonist isoproterenol and analogs of adenosine 3',5'-monophosphate (cAMP) induced a potassium current, M current, in freshly dissociated gastric smooth muscle cells. Muscarinic agonists suppress this current, apparently by acting at a locus downstream from regulation of cAMP levels by adenylate cyclase and phosphodiesterase. Thus, M current can be induced by an agent and regulated in antagonistic fashion by beta-adrenergic and muscarinic systems.