Protein kinase C requirement of Ca2+ channel stimulation by intracellular ATP in guinea-pig basilar artery smooth muscle cells.
1. Smooth muscle cells were isolated from guinea-pig basilar artery and conventional whole-cell recordings of Ca2+ channel activity were made at room temperature within 7 h of the isolation procedure. The purpose of the study was to investigate the mechanism of the stimulatory action of intracellular ATP on Ca2+ channels. 2. High (millimolar) concentrations of ATP were needed to produce stimulation of Ca2+ channels, and neither ADP nor AMP mimicked the action of ATP. 3. The ATP effect was not mimicked by stable ATP derivatives (AMP-PNP or AMP-PCP) and was abolished by incubation of cells in non-specific protein kinase inhibitors (staurosporine or H-7) or specific protein kinase C inhibitors (GF109203x, calphostin C or chelerythrine) but not by tyrosine kinase inhibitors (tyrphostin B42 and genistein). 4. The data suggest that ATP-induced stimulation of L-type Ca2+ channels requires functional activity of a protein kinase C isozyme.
McHugh
D
D
Department of Pharmacology, University of Leeds, UK.
Beech
D J
DJ
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000249:Adenosine Monophosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology*; D000818:Animals; D001488:Basilar Artery / Q000166:cytology; D002118:Calcium / Q000378:metabolism; D002120:Calcium Channel Agonists / Q000494:pharmacology*; D006168:Guinea Pigs; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000737:chemistry / Q000166:cytology* / Q000201:enzymology*; D018408:Patch-Clamp Techniques; D010766:Phosphorylation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*
D002120:Calcium Channel Agonists; D000249:Adenosine Monophosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D011493:Protein Kinase C; D002118:Calcium