Quick stretch increases the production of inositol 1,4,5-trisphosphate (IP3) in porcine coronary artery.
The present study was undertaken to know whether the formation of inositol 1,4,5-trisphosphate (IP3) is increased by quick stretch, a dynamic mechanical stimulus in porcine coronary artery in order to inquiry the possibility that IP3 could mediate Ca2+ release in the stretch-induced contraction. Quick stretching of a helical strip of porcine coronary artery at a rate of 10 cm/sec, the amount of stretch equivalent to 140% of the initial muscle length (= 100%), and the stimulus period of 30 sec with 20-min intervals, produced delayed contraction. Quick stretching increased the content of IP3 about three-fold over the control basal level, which always preceded the contraction. A putative phospholipase C inhibitor, 2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate (NCDC), abolished the increase in the formation of IP3 and partially inhibited the stretch-induced contraction. The results suggest that quick stretching increases the formation of IP3 through a possible mechanism for activation of phospholipase C, which may lead to release of Ca2+ into myoplasm and to further activation of the contractile elements.
Tanaka
Y
Y
Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Japan.
Hata
S
S
Ishiro
H
H
Ishii
K
K
Nakayama
K
K
D000109:Acetylcholine / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002219:Carbamates / Q000494:pharmacology; D003331:Coronary Vessels / Q000378:metabolism* / Q000502:physiology; D005260:Female; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D009529:Nicardipine / Q000494:pharmacology; D048448:Phenylcarbamates; D013552:Swine; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors
D000319:Adrenergic beta-Antagonists; D002219:Carbamates; D048448:Phenylcarbamates; C025508:2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate; D001285:Atropine; D015544:Inositol 1,4,5-Trisphosphate; D009529:Nicardipine; D010738:Type C Phospholipases; D000109:Acetylcholine