Effect of Diltiazem on the Transmembrane Potential of Isolated Guinea Pig Taenia Coli

Abstract

In isolated guinea pig tenia coli diltiazem, a potent coronary vasodilator, causes a decrease in the contractile force, with or without changes in the spike activity. The spike activity measured by the sucrose-gap method is the sum and synchronized discharge of the spikes of a number of cells. Intracellular recordings of the action potential from a single cell of the tenia coli were carried out to study the electrophysiological effects on smooth muscle. Diltiazem apparently interferes directly or indirectly with K permeability during the active state of membrane function.