Modulation of the accumulation of inositol phosphates and the mobilization of calcium in aortic myocytes.
In vascular smooth muscle cells the phorbol ester, 12-O-tetradecanoyl phorbol 13-acetate (TPA), a potent activator of C-kinase, inhibited the accumulation of inositol phosphates and the mobilization of calcium produced by several agonists. In the same way, TPA inhibited the fluoride-induced activation of phosphoinositide metabolism. These results suggest a C-kinase action at a post-receptor level. Moreover, the fluoride-induced accumulation of inositol phosphates shows the presence of one or more guanine nucleotide-binding proteins (G-proteins) in the regulation of receptor-phospholipase C coupling. This was confirmed by the use of N-ethylmaleimide and pertussis toxin. These results support the view that, in addition to the induction of sustained contractions, C-kinase can activate negative feedback mechanisms in aortic myocytes.
Berta
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Centre de Recherches de Biochimie Macromoléculaire, LP 8402/C.N.R.S., I.N.S.E.R.M./U 249, Faculté de Médecine, Montpellier, France.
Phaneuf
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S
Travo
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Cavadore
J C
JC
D000818:Animals; D001013:Aorta, Thoracic / Q000378:metabolism; D001572:Benzofurans; D002118:Calcium / Q000378:metabolism*; D005033:Ethylmaleimide / Q000494:pharmacology; D016257:Fura-2; D006868:Hydrolysis; D066298:In Vitro Techniques; D007295:Inositol Phosphates / Q000378:metabolism*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D037342:Pertussis Toxin; D051381:Rats; D012969:Sodium Fluoride / Q000494:pharmacology; D013403:Sugar Phosphates / Q000378:metabolism*; D010738:Type C Phospholipases / Q000378:metabolism; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D001572:Benzofurans; D007295:Inositol Phosphates; D013403:Sugar Phosphates; D010566:Virulence Factors, Bordetella; D012969:Sodium Fluoride; D037342:Pertussis Toxin; D010738:Type C Phospholipases; D005033:Ethylmaleimide; D002118:Calcium; D016257:Fura-2