Electrophysiological Study of the Striated Muscle Cells of Extrapulmonary Vein of Guinea-Pig

Electrophysiological study of the striated muscle fibers of the extrapulmonary vein of guinea-pig was carried out by means of the microelectrode technique. Membrane potentials and action potentials were slightly differed in the pulmonary vein and the atrium. The shape of the action potential of the striated muscle of the extrapulmonary vein was not resembled to that of the heart muscle. The effects of some cations and catecholamines on this striated muscle fibers were resembled to those of the atrial muscle fibers. But sometimes epinephrine and isoproterenol evoked the pacemaker activity in the extra-pulmonary vein and it was propagated to the atrium retrogradely.