Electrophysiological properties of human oviduct smooth muscle cells in dissociated cell culture.

Intracellular recordings were made from human oviduct smooth muscle maintained in cell culture. Solitary cells isolated from one another and cells in contact with one another retained electrical properties of smooth muscle in vivo. Membrane potential of solitary cells and connected cells was −35 mV. Connected cells formed electrotonic junctions which transmitted current from one cell to another. This current spread was responsible for differences in input resistance and time constant in solitary cells, 66 MΩ and 96 msec, compared to connected cells, 26 MΩ and 56 msec. All cells expressed delayed rectification to depolarizing current pulses. Some cells generated action potentials spontaneously or in response to intracellular current puleses. Action potentials were abolished by cobalt or by EGTA. Slow wave potentials, 5-20 mV in amplitude, occurred continuously once every 15 to 45 seconds in connected cells.