Publication de 4 numéros par an
ISSN Imprimer: 2155-014X
ISSN En ligne: 2155-0158
An Inhibitor of Mitochondrial Na+ − Ca2+ Exchanger CGP37157 Produces Depolarization of the Endothelial Cells with Membrane Potential Oscillations
RÉSUMÉ
We studied the effects of CGP37157, an inhibitor of mitochondrial Na+ − Ca2+ exchanger and cyclosporine A, an inhibitor of mitochondrial permeability transition pore opening,,on the membrane potential and electrical responses of intact endothelial cells from rat aorta and cultured endothelial cells. Cyclosporine A did not alter either the membrane potential of unstimulated endothelium, or the hyperpolarization in response to acetylcholine and histamine. CGP37157 induced membrane depolarization of unstimulated endothelial cells, and inhibited the sustained hyperpolarization in response to acetylcholine and histamine. In the presence of CGP37157, a transient hyperpolarization was followed by a depolarization accompanied by membrane potential oscillations of large amplitude. The latter was not observed in calcium-free medium. Our results indicate on a modulating effect of CGP37157 on endothelial cells membrane potential at rest and electrical responses to endothelium-dependent vasodilators. Possible mechanisms of CGP37157 action are discussed.