Antagonism of beta-adrenergic stimulation of L-type Ca2+ current by endothelin in guinea-pig atrial cells.
Experiments carried out with isolated guinea pig atrial cells, using the patch clamp technique, demonstrated that endothelin-1 reversed the increase in L-type Ca2+ current (ICaL) induced by isoprenaline. Similar effects of endothelin-1 were observed when ICaL was previously increased by forskolin or 8-bromo-cAMP. These results suggested that the endothelin antagonism of beta-adrenergic stimulation of ICaL was exerted independently of the cAMP-dependent phosphorylation pathway.
Delpech
N
N
Laboratoire de Physiologie Générale, CNRS URA 1869, Université de Poitiers, France.
Soustre
H
H
Potreau
D
D
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism*; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000502:physiology; D004558:Electric Stimulation; D016232:Endothelins / Q000494:pharmacology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*
D000318:Adrenergic beta-Agonists; D015220:Calcium Channels; D016232:Endothelins; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate; D000242:Cyclic AMP; D007545:Isoproterenol