Effects of haloperidol and clotrimazole on synaptic transmission in and contractile activity of smooth muscles of the guinea-pig intestine

Abstract

In muscle strips of the guinea-pig large intestine, haloperidol and clotrimazole increased spontaneous electrical and contractile activities and decreased ATP-evoked hyperpolarization of smooth-muscle cells and the amplitude of inhibitory synaptic potentials. The pattern of effects of haloperidol on hyperpolarization induced by intramural stimulation of muscle strips was preserved under conditions of pre-incubation of the preparations in Krebs solutions containing pyridoxal-5′-phosphate, Nω-nitro-L-arginine, or apamin, as well as both apamin and tetraethylammonium.