[Calcium sensitivity of vascular smooth muscle and effects of drugs].
It has been believed that cytosolic Ca2+ level ([Ca2+]i) is the only regulator of smooth muscle contraction. Measuring [Ca2+]i and muscle force simultaneously, it is evident that changes in Ca2+ sensitivity of contractile elements is also an important regulator. Although the mechanisms for Ca2+ sensitization is not fully understood yet, Ca2+ sensitization of myosin phosphorylation and activation of a Ca(2+)-sensitive mechanism which is not dependent on myosin phosphorylation have been proposed. Receptor-agonists seem to activate both of these mechanisms although protein kinase C does not necessary be involved in these mechanisms.
Karaki
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D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000502:physiology; D015220:Calcium Channels / Q000378:metabolism; D015237:Dinoprost / Q000494:pharmacology; D016232:Endothelins / Q000494:pharmacology; D006801:Humans; D009119:Muscle Contraction; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009218:Myosins / Q000378:metabolism; D009638:Norepinephrine / Q000494:pharmacology*; D010703:Phorbol Esters / Q000494:pharmacology; D010766:Phosphorylation; D014700:Verapamil / Q000494:pharmacology
D015220:Calcium Channels; D016232:Endothelins; D010703:Phorbol Esters; D015237:Dinoprost; D014700:Verapamil; D009218:Myosins; D002118:Calcium; D009638:Norepinephrine