Electrogenesis of freshly explanted spontaneously active clusters of neonatal rat ventricle cells.

Spontaneously active explanted rat ventricle cells show 4 to 7 h after explantation fast rising TTX sensitive action potentials but 24 h after explantation, electrogenesis is determined by slow rising. Mn sensitive action potentials. Because 4 to 7 h after explantation the electrical properties of the cells resemble more those of the tissue they were derived from than of cells 24 h after explantation, we conclude that the occurrence of slow rising action potentials is not directly related to the method of tissue disintegration but develops gradually after explantation.