Objective To determine whether matrine, a kind of traditional Chinese medicinal alkaloid, can relax the aortic smooth muscles isolated from guinea pigs and to investigate the mechanism of its relaxant effects. Methods...Objective To determine whether matrine, a kind of traditional Chinese medicinal alkaloid, can relax the aortic smooth muscles isolated from guinea pigs and to investigate the mechanism of its relaxant effects. Methods Phenylephrine or potassium chloride concentration-dependent relaxation response of aortic smooth muscles to matrine was studied in the precontracted guinea pigs. Results Matrine （1×10^-4 mol/L -3.3×10^-3 mol/L） relaxed the endothelium-denuded aortic rings pre-contracted sub-maximally with phenylephrine, in a concentration-dependent manner, and its pre-incubation （3.3× 10^- 3 mol/L） produced a significant rightward shift in the phenylephrine dose-response curve, but had no effects on the potassium chloride-induced contraction. The anti-contractile effect of matrine was not reduced by the highly selective ATP-dependent K^＋ channel blocker glibenclamide （10.5 mol/L）, either by the non-selective K^＋channel blocker tetraethylammonium （10^-3 mol/L）, or by the β-antagonist propranolol （10^-5 mol/L）. In either ＂normal＂ or ＂Ca^2＋-free＂ bathing medium, the phenylephrine-induced contraction was attenuated by matrine （3.3×10^-3 mol/L）, indicating that the vasorelaxation was due to inhibition of intracellular and extracellular Ca^2＋ mobilization. Conclusion Matrine inhibits phenylephrine-induced contractions by inhibiting activation of α-adrenoceptor and interfering with the release of intracellular Ca^2＋ and the influx of extracellular Ca^2＋.展开更多
Objective The present in vivo study was undertaken to determine whether matrine,a kind of traditional Chinese medicinal alkaloid,would relax the isolated guinea pig aortic smooth muscles,if so,to investigate the mecha...Objective The present in vivo study was undertaken to determine whether matrine,a kind of traditional Chinese medicinal alkaloid,would relax the isolated guinea pig aortic smooth muscles,if so,to investigate the mechanism involved.Methods The concentration-dependent relaxation response to matrine was studied in phenylephrine or potassium chloride precontracted guinea pig aortic rings.Results Matrine(1×10-4 M-3.3×10-3 M)relaxed the endothelium denuded aortic rings precontracted submaximally with phenylephrine,in a concentration-dependent manner,and it's preincubation(3.3×10-3 M)produced a significant rightward shift in the phenylephrine dose-response curve,but had no effects on the potassium chloride-induced contraction.The anticontractile effect of matrine was not reduced by the highly selective ATP-dependent K+ channel blocker glibenclamide(10-5 M),the non-selective K+ channel blocker tetraethylammonium(10-3 M),as well as the β-antagonist propranolol(10-5 M).In either "normal" or "Ca2+-free" bathing medium,the phenylephrine-induced contraction was attenuated by matrine(3.3×10-3 M),indicating the vasorelaxation was due to inhibit of intracellular and extracellular Ca2+ mobilization.Conclusions The results obtained clearly demonstrated that matrine inhibits phenylephrine-induced contractions by inhibiting activation of α-adrenoceptor and interfering with both the release of intracellular Ca2+ and the influx of extracellular Ca2+.展开更多
基金supported by the Program for New Century Excellent Talents in Universities of the Ministry of Education of China (NCET-06-0916)Ningxia Natural Science Foundation (NZ0782)Ningxia Academic Scientific Research Program (2005-2007)
文摘Objective To determine whether matrine, a kind of traditional Chinese medicinal alkaloid, can relax the aortic smooth muscles isolated from guinea pigs and to investigate the mechanism of its relaxant effects. Methods Phenylephrine or potassium chloride concentration-dependent relaxation response of aortic smooth muscles to matrine was studied in the precontracted guinea pigs. Results Matrine （1×10^-4 mol/L -3.3×10^-3 mol/L） relaxed the endothelium-denuded aortic rings pre-contracted sub-maximally with phenylephrine, in a concentration-dependent manner, and its pre-incubation （3.3× 10^- 3 mol/L） produced a significant rightward shift in the phenylephrine dose-response curve, but had no effects on the potassium chloride-induced contraction. The anti-contractile effect of matrine was not reduced by the highly selective ATP-dependent K^＋ channel blocker glibenclamide （10.5 mol/L）, either by the non-selective K^＋channel blocker tetraethylammonium （10^-3 mol/L）, or by the β-antagonist propranolol （10^-5 mol/L）. In either ＂normal＂ or ＂Ca^2＋-free＂ bathing medium, the phenylephrine-induced contraction was attenuated by matrine （3.3×10^-3 mol/L）, indicating that the vasorelaxation was due to inhibition of intracellular and extracellular Ca^2＋ mobilization. Conclusion Matrine inhibits phenylephrine-induced contractions by inhibiting activation of α-adrenoceptor and interfering with the release of intracellular Ca^2＋ and the influx of extracellular Ca^2＋.
文摘Objective The present in vivo study was undertaken to determine whether matrine,a kind of traditional Chinese medicinal alkaloid,would relax the isolated guinea pig aortic smooth muscles,if so,to investigate the mechanism involved.Methods The concentration-dependent relaxation response to matrine was studied in phenylephrine or potassium chloride precontracted guinea pig aortic rings.Results Matrine(1×10-4 M-3.3×10-3 M)relaxed the endothelium denuded aortic rings precontracted submaximally with phenylephrine,in a concentration-dependent manner,and it's preincubation(3.3×10-3 M)produced a significant rightward shift in the phenylephrine dose-response curve,but had no effects on the potassium chloride-induced contraction.The anticontractile effect of matrine was not reduced by the highly selective ATP-dependent K+ channel blocker glibenclamide(10-5 M),the non-selective K+ channel blocker tetraethylammonium(10-3 M),as well as the β-antagonist propranolol(10-5 M).In either "normal" or "Ca2+-free" bathing medium,the phenylephrine-induced contraction was attenuated by matrine(3.3×10-3 M),indicating the vasorelaxation was due to inhibit of intracellular and extracellular Ca2+ mobilization.Conclusions The results obtained clearly demonstrated that matrine inhibits phenylephrine-induced contractions by inhibiting activation of α-adrenoceptor and interfering with both the release of intracellular Ca2+ and the influx of extracellular Ca2+.
