Phorbol Ester Modulates th Action of Acetylcholine in Rabbit Carotid Artery.
- Author:
Yong Lae NHO
1
;
Sang Ho LEE
;
Young Woo LEE
Author Information
1. Department of Neurosurgery, College of Medicine, Pusan National University, Pusan, Korea.
- Publication Type:Original Article
- Keywords:
Phorbol ester;
Acetylcholine;
Protein kinase C;
Contraction of smooth muscle;
Endothelium derived relaxing factor(EDRF)
- MeSH:
Acetylcholine*;
Baths;
Carotid Arteries*;
Endothelium;
Membranes;
Methylene Blue;
Muscle, Smooth;
Protein Kinase C;
Sodium;
Staurosporine;
Vasodilation
- From:Journal of Korean Neurosurgical Society
1994;23(12):1359-1368
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
Authors studied the regulatory mechanism of protein kinase C on the action of acetylcholine in rabbit carotid artery. The arterial rings were myographied isometrically in an isolated organ bath. In this study, acetylcholine relaxed phenylephrine-induced contraction of rabbit carotid artery in the presence of endothelium. In the pretreatment of methylene blue or nitro-L-arginine, the action of acetylchioline was reduced. Pretreatment of phorbol 12-myristate 13-acetate(PMA) attenuated the action of acetylcholine, but PMA did not attenuated it in the presence of staurosporine, suggesting that protein kinase C suppressed the action of acetylcholine. The potency of phorbol ester on the action of acetylcholine was PMA>phorbol 12, 13-dibutyrate(PDBu)>phorbol 12,13-diacetate(PDA), but the direct effect of phorbol on the contraction of arterial rings was PDBu>PMA>PDA. This implied that protein kinase C involved in the contraction of smooth muscle and the attenuation of the action of acetylcholine were different. PMA did not affect on A23187- and sodium nitroprusside-induced vasorelaxation. Acetylcholine increased tissue cGMP contents, which was reduced by PMA. These results suggest that in rabbit carotid artery protein kinase C reduce acetylcholine-stimuated endothelium derived relaxing factor(EDRF) release by affecting membrane receptor, and do not affect on the function of EDRF and cGMP production in the smooth muscle.
