Relationship between intracellular Ca2+ store and protein kinase C in agonist-induced contraction of hypertensive rat aortae.
The roles of intracellular Ca2+ store and protein kinase C (PKC) in vascular contractile responses independent of Ca2+ influx were studied using aortic rings from spontaneously hypertensive rat (SHR) and Wistar-Kyoto rat (WKY). The functional sizes of agonist-sensitive intracellular Ca2+ store were estimated as the peak response to agonist after PKC inhibition with calphostin C (Cal-C), a PKC inhibitor. The participation of PKC in 5-hydroxytryptamine-, phenylephrine-, and endothelin-1 (ET-1)-induced contractions in aortae of SHR was equal to, or greater than that in WKY. In contrast, compared with WKY, SHR aortae possessed a greater size of endothelin-1-sensitive Ca2+ store, a similar size of 5-hydroxytryptamine-sensitive Ca2+ store, and a smaller size of phenylephrine sensitive Ca2+ store. Based on these data, both PKC activation and functional size of intracellular Ca2+ store differ between SHR and WKY and these differences are selective among agosists.
Shimamoto
H
H
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Shimamoto
Y
Y
Daniel
E E
EE
Kwan
C Y
CY
D000818:Animals; D001011:Aorta / Q000201:enzymology*; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002273:Carcinogens / Q000494:pharmacology; D019332:Endothelin-1 / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000201:enzymology*; D009281:Naphthalenes / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012508:Sarcolemma / Q000201:enzymology; D012701:Serotonin / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D002273:Carcinogens; D019332:Endothelin-1; D004791:Enzyme Inhibitors; D007211:Indoles; D009281:Naphthalenes; D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D012701:Serotonin; D011493:Protein Kinase C; C058819:calphostin C; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium; C000543:cyclopiazonic acid