【摘要】 目的:研究葡萄籽提取物原花青素（procyanidins,PC）舒张家兔离体主动脉和降低其动脉血压的作用及机制。方法:采用家兔离体胸主动脉环灌流模型,将标本分6组:去内皮、内皮完整、吲哚美辛(1×10^-1mol·L^-1)、普萘洛尔(1×10^-5mol·L^-1)、左旋硝基精氨酸N^ω-nitro-L-arginine(L-NNA 1×10^-4mol·L^-1)或甲烯蓝(MB 1×10^-5mol·L^-1),分别累积加入1.25,2.5,5.0 mg·L^-1PC观察血管张力变化;并观察40 mg·L^-1PC对去甲肾上腺素（NA）(1×10^-8～1×10^-5mol·L^-1)、KCl(6.3～100 mmol·L^-1)和CaCl₂(1×10^-5～1×10^-2mol·L^-1)诱导血管环收缩曲线的影响。另用家兔颈总动脉插管法,经静脉累积注射4.0,8.0,16,32,64,84 mg·kg^-1PC后观察血压变化。结果:PC能舒张主动脉血管,并有量效依赖性（r=0.63,P<0.001）,去内皮、L-NNA或MB可减弱PC的舒张作用。PC能抑制NA,KCl和CaCl₂的量效收缩反应。PC能降低家兔正常动脉血压并有量效依赖性（r= 0.92,P<0.001）。结论:PC舒张血管的作用是通过抑制细胞内Ca²⁺释放和电压依赖性Ca²⁺通道而减少Ca²⁺内流;也与内皮释放的NO有关;PC可降低家兔正常的动脉血压。更多还原

【Abstract】 Objective:To study the vasodilation effect of the procyanidin（PC）extracted from grape seeds on rabbit thoracic aortic rings in vitro,decreasing blood pressure in vivo and the possible mechanism.Method:Rabbits aortic rings were isolated and were divided into six groups including removal of endothelium,integrity of endothelium,1×10^-5mol·L^-1indomethacin（Indo）,1×10^-5mol·L^-1propranolol（Prop）,1×10^-4mol·L^-1N^ω-nitro-L-arginine（L-NNA）and 1×10^-5mol·L^-1methylene blue（MB）. Then the thoracic aortic rings were treated with PC with cumulative concentrations of 1.25,2.5,5.0 mg·L^-1respectively and the changes of tension were recorded,and investigate the effect of 40 mg·L^-1PC on the contraction of aortic smooth muscles,thoracic aortic rings were pre-treated with NA(1×10^-8～1×10^-5mol·L^-1),KCI(6.3～100 mmol·L^-1)and CaCl₂(1×10^-5～1×10^-2 mol·L^-1)followed by treatment with PC.Then,rabbits common carotid artery was intubated and arterial blood pressure in vivo was recorded.PC with cumulative concentrations of 4.0,8.0,16,32,64,84 mg·kg^-1was injected into vein and the changes of arterial blood pressure were observed.Result:PC could relax isolated rabbit aorta and showedan obvious concentration-dependent relaxation（r =0.63,P<0.001）.The relaxant effect of PC was significantly reduced by removal of endothelium and by treatment with nitric oxide synthase inhibitor L-NNA,or guanylyl cyclase inhibitor MB.In addition PC could decrease the dose response curves of aortic rings to NA,KCI and CaCl₂.PC has a significant concentration-dependent negative effect on arterial blood pressure in vivo（r=0.92,P<0.001）.Conclusion:PC has a vasodilation effect not only in an endothelium-dependent,nitric oxide involved manner,but in inhibi- tion of calcium release and blockage of potential-dependent calcium channels.PC could decrease the rabbit’s arterial blood pressure sig- nificantly in vivo.更多还原