Modulation of cardiac cell Ca2+ currents by PAF.
Using the whole-cell voltage clamp technique, PAF was found to stimulate T- and L-type Ca2+ currents in a dose dependent manner in both human and chick ventricular single cells. However, PAF had no effect on either the fast sodium current or the delayed outward K+ current in these heart cells. The effect of PAF on both Ca2+ currents was blocked by the PAF receptor antagonist WEB2170. Treatment of single ventricular cells with Pertussis toxin (PTX) prevented stimulation of T- and L-type calcium currents by PAF. These results suggest that there are functional PAF receptors in both human and chick ventricular cells. The stimulation of both types of Ca2+ currents seems to be mediated via a PTX sensitive G-protein.
Bkaily
G
G
Department of Anatomy and Cell Biology, Faculty of Medicine, University of Sherbrooke, Quebec, Canada.
Wang
S
S
Bui
M
M
Stankova
J
J
Rola-Pleszczynski
M
M
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism*; D002478:Cells, Cultured; D002642:Chick Embryo; D017136:Ion Transport / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D010972:Platelet Activating Factor / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism
D015220:Calcium Channels; D010972:Platelet Activating Factor; D011188:Potassium; D002118:Calcium