ET-1 stimulates Ca2+ currents in cardiac cells.
Using the whole-cell voltage-clamp technique, endothelin (ET-1) was found to stimulate T- and L-type Ca2+ currents in a dose-dependent manner in both human and chick ventricular single cells. However, ET-1 had no effect on both the fast sodium current and the delayed outward K+ current in these cells. The effect of ET-1 on both Ca2+ currents was blocked by the ET(A) receptor antagonist BQ123. Treatment of single ventricular cells with pertussis toxin (PTX) prevented stimulation of T- and L-type calcium currents by ET-1. These results suggest that there are functional ET(A) receptors in both human and chick ventricular cells. The stimulation of both types of Ca2+ currents appears to be mediated by a PTX-sensitive G-protein.
Bkaily
G
G
Department of Physiology and Biophysics, Faculty of Medicine, University of Sherbrooke, Québec, Canada.
Wang
S
S
Bui
M
M
Ménard
D
D
D000818:Animals; D015220:Calcium Channels / Q000187:drug effects*; D002642:Chick Embryo; D016232:Endothelins / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D006801:Humans; D010456:Peptides, Cyclic / Q000494:pharmacology; D037342:Pertussis Toxin; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D015220:Calcium Channels; D016232:Endothelins; D010456:Peptides, Cyclic; D010566:Virulence Factors, Bordetella; D037342:Pertussis Toxin; C072247:cyclo(Trp-Asp-Pro-Val-Leu)