【摘要】 背景:动脉血管平滑肌细胞膜电位的微小变化就可以导致张力的显著性改变,膜去极化与高血压形成有密切关系。目的:研究易卒中型自发性高血压大鼠大脑中动脉平滑肌细胞的静息膜电位(Em)及其对血管活性物质KCl、去甲肾上腺素的反应性。设计:对照分析动物实验。单位:山东省医学科学院药物研究所。材料:雄性卒中型自发性高血压大鼠18只和雄性Wistar大鼠26只。方法:①两组大鼠经乌拉坦(1g/kg)腹腔注射麻醉,迅速取出大脑,剥离出大脑中动脉,应用细胞内微电极记录血管平滑肌细胞膜电位。②分别观察不同浓度的KCl(10,20,50mmol/L),去甲肾上腺素(10-7,10-6,10-5mol/L)对血管平滑肌细胞膜电位的影响。主要观察指标:①两组大鼠血管平滑肌细胞膜电位。②不同浓度的KCl和去甲肾上腺素对血管平滑肌细胞膜电位的影响。结果:①卒中型自发性高血压大鼠膜电位明显低于Wistar大鼠[(-48.2±3.1),(-64.4±4.3)mV]。②KCl(10,20,50mmol/L)和去甲肾上腺素(10-7,10-6,10-5mol/L)均引起大脑中动脉膜电位去极化,且皆呈剂量依赖式特点;与Wistar大鼠比较,卒中型自发性高血压大鼠的大脑中动脉反应性明显增强。结论:卒中型自发性高血压大鼠大脑中动脉血管平滑肌细胞膜电位较低,对KCl和去甲肾上腺素的反应性明显高于Wistar大鼠。更多还原

【Abstract】 BACKGROUND: The small change of the membrane potential (Em) of vascular smooth muscle cells (VSMC) could result in significant alteration in tension,and the membrane depolarization was closely associated with the development of hypertension. OBJECTIVE: To study the resting Em of VSMC from the middle cerebral artery (MCA) of stroke-prone spontaneously hypertensive rats (SHRSP) and the reactivity of Em to KCl and norepinephrine (NE). DESIGN: An animal experiment of comparative analysis. SETTING: Institute of Materia Medica,Shandong Academy of Medical Sciences. MATERIALS: Eighteen male SHRSP and 26 male Wistar rats were used. METHODS: 1 Rats in both groups were anesthetized with intraperitoneal injection of ethyl carbamate (1 g/kg),the brains were removed quickly,and the Em of VSMC was recorded by intracellular microelectrodes. 2 The effects of different concentrations of KCl (10,20,50 mmol/L) and NE (10-7,10-6,10-5 mol/L) on the Em of VSMC were observed. MAIN OUTCOME MEASURES: 1 Em of VSMC in both groups 2 Effects of different concentrations of KCl and NE on the Em of VSMC. RESULTS: 1 The Em was obviously lower in SHRSP than in the Wistar rats (-48.2±3.1),(-64.4±4.3) mV. 2 Both KCl (10,20,50 mmol/L) and NE (10-7,10-6,10-5 mol/L) could cause the depolarization of Em of MCA in a concentration-dependent manner. The reactivity to MCA of SHRSP was obviously increased as compared with the Wistar rats. CONCLUSION: The resting Em of VSMC from the MCA of SHRSP was lower,and the reactivity of VSMC to KCl and NE was significantly stronger than that of Wistar rats.更多还原