Interaction of phenoxybenzamine with muscarinic receptors and calcium channels.

Phenoxybenzamine (POB, 10(-6) - 10(-4) M) inhibited the responses of guinea pig ileal longitudinal smooth muscle to both muscarinic agonists and K+-depolarization but was more effective against the agonist-induced responses. POB inhibited binding of both the muscarinic antagonist [3H]quinuclidinyl benzilate (QNB) and the Ca2+ channel antagonist [3H… (More)