[Electrophysiological properties of intact endothelial cells from rat inferior vena cava]

Membrane potential has been recorded from endothelial cells of the rat inferior vena cava. The resting membrane potential of venous endothelial cells was 69 +/- 4 mV, which was about 20 mV more negative than resting potential of rat arterial endothelial cells measured under the same experimental conditions. 40% of the vein studied demonstrated spontaneous oscillations of endothelial membrane potential. These oscillations were found to be Ca2+ action potentials generated in the vein smooth muscle and electrotonically transferred into the endothelial cells.