[Role of protein kinase C in regulating smooth muscle electrical and contractile activity: the effect of phorbol ester].
The effects of protein kinase C activation by 12-O-tetra-decanoyl-phorbol-13-acetate (TPA) on the functions of guinea-pig smooth muscle taenia coli have been studied, using double-sucrose-gap method. A 15-20-min treatment of the muscle with 2 X 10(-8) M TPA caused a progressing inhibition of spontaneous electrical activity and mechanical tension, suppression of post-hyperpolarizing electrical and contractile "off-responses", a decrease in the number of action potentials during superthreshold membrane depolarization, depression of electrical and mechanical responses induced by acetylcholine, histamine, bradykinin mediators. The treatment of pre-depolarized (140 mM kappa+) muscle with 2.10(-8) TPA has led to a considerable reduction in contractile responses induced by the above mediators. The results obtained indicate that protein kinase C is capable of regulating both voltage-sensitive and receptor-operated ionic channels in smooth muscle cells.
D000818:Animals; D002118:Calcium / Q000378:metabolism; D006168:Guinea Pigs; D007473:Ion Channels / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D010703:Phorbol Esters / Q000494:pharmacology*; D011493:Protein Kinase C / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D007473:Ion Channels; D010703:Phorbol Esters; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium
Rol' proteinkinazy C v reguliatsii élektricheskoĭ i sokratitel'noĭ aktivnosti gladkoĭ myshtsy: éffekt forbolovogo éfira.