Bovine chromaffin cells possess FTX-sensitive calcium channels.
The effects of the synthetic analogue of the toxin from the venom of the funnel-web spider Agenelopsis aperta (sFTX) on whole-cell Ba2+ currents through Ca2+ channels were studied in cultured bovine chromaffin cells. sFTX selectively and reversibly blocked a significant component (55 +/- 3%) of the whole-cell IBa. Effects of sFTX were additive to those of omega-conotoxin GVIA, a selective blocker of N-type Ca2+ channels, and those of furnidipine, a novel dihydropyridine L-type Ca2+ channel blocker. We conclude that the cultured bovine chromaffin cells, in addition to N- and L-type Ca2+ channels, possess a P-type component in their whole-cell currents through their Ca2+ channels.
Departamento de Fisiología y Farmacología, Universidad de Salamanca, Spain.
L
L
Gandía
A
A
Albillos
A G
AG
García
D000313:Adrenal Medulla / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D001464:Barium / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D002417:Cattle; D002478:Cells, Cultured; D004095:Dihydropyridines / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D015640:Ion Channel Gating / Q000187:drug effects; D007700:Kinetics; D010455:Peptides / Q000494:pharmacology; D011073:Polyamines / Q000494:pharmacology*; D020960:omega-Conotoxins
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D004095:Dihydropyridines; C071920:FTX, spider toxin; D010455:Peptides; D011073:Polyamines; D020960:omega-Conotoxins; C053423:Conus magus toxin; D001464:Barium; C082391:furnidipine