Authors: Jinyan Zhang Yongxiao Cao Weiliang Weng Yikui Li Le Zhao
Publish Date: 2013/07/02
Volume: 19, Issue: 7, Pages: 510-516
Abstract
Rats were anaesthetized and sacrificed The superior mesenteric artery was removed dissected free of adherent tissue and cut into 20 mm long cylindrical segments Isometric tension of artery rings was recorded by a myograph system in vitro Concentrationrelaxation curves of paeonol 178 μ mol/L to 316 mmol/L were recorded on artery rings precontracted by potassium chloride KCl and concentrationcontraction curves of KCl 5hydroxytryptamine 5HT noradrenaline NA or calcium chloride CaCl2 were recorded in the presence of paeonol 10−45 10−38 10−35 mol/L respectively And also concentrationrelaxation curves of paeonol were recorded in the presence of different potassium channel inhibitors and propranolol on rings precontracted with KCl respectively To investigate the role of intracellular Ca2+ release from Ca2+ store the contraction induced by NA 100 μ mol/L and CaCl2 2 mmol/L in Ca2+ free medium was observed in the presence of paeonol respectivelyPaeonol relaxed artery rings precontracted by KCl in a concentrationdependent manner and the vasodilatation effect was not affected by endothelium denudation Paeonol significant decreased the maximum contractions Emax induced by KCl CaCl2 NA and 5HT as well as Emax induced by NA and CaCl2 in Ca2+ free medium suggesting that paeonol dilated the artery via inhibiting the extracellular Ca2+ influx mediated by voltagedependent calcium channel and receptormediated Ca2+influx and release Moreover none of glibenclamide tetraethylammonium barium chlorded and propranolol affected the paeonolinduced vasodilatation indicating that the vasodilatation was not contributed to ATP sensitive potassium channel calciumactivated potassium channel inwardly rectifying potassium channel and βadrenoceptor
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