通心络对高血压大鼠血管内皮功能的保护作用

目的探讨通心络对高血压大鼠血管内皮的保护作用。方法实验动物分为3组,自发性高血压大鼠（SHR）组,SHR服用通心络（TXL）组和正常血压大鼠（WKY）组。通过放免及聚合酶链反应检测主动脉一氧化氮（NO）、内皮素（ET-1）、血管内皮生长因子（VEGF）基因表达。结果SHR组NO水平低于WKY组（P<0.05）,TXL组NO水平高于SHR组（P<0.05）。SHR组ET-1含量及mRNA均高于WKY组（P<0.05）,TXL组ET-1含量及mRNA表达低于SHR组（P<0.05）,SHR组及TXL组的mRNA表达均高于WKY组（P<0.05）,以SHR组为最高。结论通心络可能对高血压大鼠的内皮功能有保护作用。     

通心络对高血压大鼠血管内皮功能的保护作用研究

目的 探讨通心络对高血压大鼠血管内皮的保护作用.方法 实验动物分为3组,分别为自发性高血压大鼠组(SHR组),SHR服用通心络组(TXL组)和正常血压大鼠组(WKY组).通过放射免疫及聚合酶链反应检测主动脉一氧化氮(NO)、内皮素(ET)、血管内皮生长因子(VEGF)基因表达.结果 SHR组NO水平低于WKY组,TXL组NO水平高于SHR组.SHR组及TXL组mRNA表达均高于WKY组,以SHR组为最高.结论 通心络可能对高血压大鼠血管内皮功能有保护作用.     

通心络对自发性高血压大鼠血管内皮功能的影响

目的 观察通心络胶囊对自发性高血压大鼠(SHR)血管内皮功能的保护作用.方法 将24只SHR随机分为通心络组(TXL组)、咪达普利组(MD组)和生理盐水组(SHR组),每组8只.同时还有8只同龄Wistar-Kyoto(WKY)大鼠作为正常对照组.TXL组和MD组分别以通心络胶囊280 mg/(kg·d)和咪达普利0.90 mg/(kg·d)配成2 mL水溶液灌胃4周.SHR组与WKY组灌胃等量生理盐水.实验结束后取血测定内皮素-1(ET-1)、一氧化氮(NO)、血管紧张素Ⅱ(AngⅡ)、丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性.结果 SHR组NO浓度与SOD活性均低于WKY组(P<0.01),TXL组NO浓度与SOD活性则高于SHR组(P<0.01),SHR组ET-1、AngⅡ及MDA水平高于WKY组(P<0.01),TXL组ET-1、AngⅡ及MDA水平均低于SHR组,与MD组比较则无统计学意义(P>0.05).结论 通心络胶囊可能通过增加NO浓度和SOD活性,降低ET-1、AngⅡ及MDA水平,对血管内皮具有保护作用.     

女贞子、淫羊藿补肾中药对自发性高血压大鼠主动脉内皮舒缩功能的影响

目的 研究补肾中药女贞子、淫羊藿对自发性高血压大鼠(SHR)的血压、主动脉内皮舒张因子一氧化氮(NO)及收缩因子内皮素(ET-1)的影响,探讨补肾中药调节主动脉内皮舒缩功能的可能机制.方法 采用随机对照研究的方法将40只12~14周龄自发性高血压大鼠(SHR)随机分为女贞子组、淫羊藿组、阳性对照组、模型组,以同龄同种系正常血压的京都种大鼠(Wistar-Kyoto rat,WKY)10只作为正常组;女贞子组、淫羊藿组、阳性对照组分别给予女贞子、淫羊藿水煎液,依那普利水溶液,模型组和正常组给予蒸馏水灌胃.2 w后采用多导生理记录仪检测大鼠血压,处死大鼠后取腹主动脉血测定血清一氧化氮(NO),血浆内皮素-1(ET-1)的含量,取主动脉检测内皮eNOS、ET-1蛋白及eNOS mRNA、ET-1mRNA的表达.结果 用药后女贞子、淫羊藿使SHR大鼠的血压有所降低,但差异无统计学意义;女贞子组、淫羊藿组血液NO、主动脉内皮eNOS蛋白及eNOS mRNA表达较模型组升高(P<0.05),血液ET、主动脉内皮ET-1蛋白及ET-1 mRNA表达均明显降低(P<0.05).结论 单味中药女贞子、淫羊藿虽然没有明显降低血压,但略有下降的趋势,且能调节主动脉血管内皮舒缩因子.     

束缚应激对大鼠主动脉5-HT_(1D)和5-HT_(2A)受体表达的影响及通心络、薤白提取物的干预作用

目的观察束缚应激对大鼠主动脉5-HT1D和5-HT2A受体表达的影响及通心络和薤白提取物的干预作用。方法健康W istar大鼠60只,随机分为对照组、束缚应激组、薤白组、通心络组。观察大鼠一般状况、主动脉内皮细胞形态和结构,检测血中ET-1和NO水平,采用Real Time PCR和Western印迹检测主动脉5-HT1D和5-HT2A受体基因和蛋白表达。结果束缚应激所致抑郁状态可导致血管内皮结构和分泌功能损伤,同时5-HT1D mRNA和蛋白表达降低,5-HT2A mRNA和蛋白表达升高;通心络和薤白提取物可有效保护血管结构和功能,调节主动脉5-HT1D和5-HT2A受体基因和蛋白表达。结论通心络和薤白提取物可通过增强介导舒血管作用的5-HT1D mRNA和蛋白表达,抑制介导缩血管作用的5-HT2A mRNA和蛋白表达,从而对抑郁状态大鼠血管内皮功能发挥保护作用。     

沙格列汀降低自发性高血压大鼠血压的效果及作用机制

目的探讨沙格列汀降低自发性高血压大鼠(SHR)血压的效果及作用机制。方法选择30只SHR,按随机数字表法分为干预组和对照组(n=15),同时选择15只Wistar-Kyoto(WKY)大鼠作为WKY组。干预组大鼠每日给予剂量为10 mg/kg的沙格列汀灌胃处理,同期给予对照组及WKY组等体积的超纯水,均持续8 w。以无创伤血压测定仪测量三组大鼠处理前后的尾动脉收缩压(SBP),测量间期2 w;显微镜下观察主动脉的病理形态学变化;分别采用放射免疫法、酶联免疫法、硝基还原法检测血浆中的胰高血糖素样肽(GLP)-1、内皮素(ET)-1和一氧化氮(NO)水平。结果 (1)干预组SBP随处理时间的延长逐渐降低,而对照组逐渐升高,且干预组处理后的SBP均低于同期对照组,而仍高于同期WKY组(P0.05)。(2)显微镜下观察显示,对照组和干预组均表现不同程度的平滑肌细胞增生肥大、内膜增厚,但干预组较对照组有所改善。(3)8 w后干预组大鼠的血浆GLP-1水平均显著高于WKY组及对照组(P0.05);对照组和干预组的ET-1水平较WKY组明显升高,NO水平明显降低,而干预组ET-1水平低于对照组,NO水平高于对照组(P0.05)。结论沙格列汀可降低SHR的动脉血压,其机制可能与抑制ET-1的释放、促进NO的合成有关。     

通心络对自发性高血压大鼠阻力血管结构的影响

目的观察通心络对自发性高血压大鼠(SHR)的血压、阻力血管结构的影响.方法30只12周龄雄性SHR大鼠,随机分成3组:(1)大剂量通心络组(n=10,通心络1.5 g/kg·d);(2)小剂量通心络组(n=10,通心络0.5 g/kg·d);(3)SHR空白对照组(n=10);(4)同龄雄性正常血压WKY大鼠对照组(n=10).用无创法测定尾动脉收缩压及心率,至给药12周处死.测定肠系膜动脉分支第3级血管壁(中膜)/腔面积比(W/L).结果与SHR对照组相比大小剂量通心络组,均能在一定程度上抑制SHR血压升高[184.3±15.1,163.2±9.8 vs 226.9±14.9)mm Hg,P＜0.05].通心络组治疗后能使SHR大鼠的肠系膜3级血管的血管腔/壁比(L/W)减少.结论通心络可以抑制SHR阻力血管肥厚.     

疲劳应激对血管内皮功能障碍大鼠脂蛋白相关磷脂酶A2含量和4型G蛋白耦联受体表达的影响及通络干预的作用

目的方法探讨通络干预对疲劳应激致内皮功能障碍大鼠血清脂蛋白相关磷脂酶A2(lp-PLA2)水平和主动脉4型G蛋白耦联受体(GPR4)表达的影响。方法将60只雄性Wistar大鼠随机分为正常对照组、疲劳应激组、人参组和通心络组。采用"基础饮食+负重力竭游泳"方法建立疲劳应激模型。通过游泳时间、爬杆时间评价模型建立,扫描电镜观察血管内皮形态,并检测一氧化氮(NO)、内皮素(ET)评价内皮功能;应用ELISA方法检测血清lp-PLA2水平,应用Real Time PCR和Western印迹分析检测主动脉GPR4 mRNA、蛋白表达水平。结果疲劳应激组血管内皮结构损伤,内皮分泌NO明显减少,ET明显增加(均P<0.05)。疲劳应激组血清lp-PLA2水平显著升高(P<0.01),主动脉GPR4 mRNA和蛋白表达水平明显高于正常对照组(P<0.05)。人参、通心络干预后,血清NO水平明显增加,血浆ET含量明显降低(均P<0.01);血清lp-PLA2水平明显下降(均P<0.01),主动脉GPR4表达水平显著下降(均P<0.05)。结论疲劳应激模型大鼠血管内皮出现明显损伤,血清lp-PLA2含量明显增加,主动脉GPR4 mRNA和蛋白表达水平明显升高。通络治疗能显著降低疲劳应激大鼠血清lp-PLA2水平,抑制主动脉GPR4 mRNA和蛋白表达,因此通络治疗可有效抑制ox-LDL对血管内皮的损伤。     

黄嘌呤氧化酶对血管内皮功能障碍的影响

目的考察黄嘌呤氧化酶(xanthine oxidase)在自发性高血压大鼠(SHR)血管舒缩及内皮功能障碍中的作用。方法采用尾套法测定SHR和正常大鼠(WKY)血压;Greiss反应测定血清一氧化氮分泌量;FRAP(ferric reduction abilitypower)法测定主动脉蛋白总抗氧化能力;RT-PCR法考察黄嘌呤氧化酶及内皮型一氧化氮合酶(eNOS)mRNA表达情况;血管环舒缩测定来评价黄嘌呤氧化酶抑制剂别嘌呤醇(oxypurinol,Oxy)对大鼠腹主动脉内皮依赖性舒张反应的影响。结果SHR血压(191.1±5.6)显著高于WKY大鼠(140.4±5.9)mmHg;SHR血清NO分泌量(28.4±5.4)、主动脉蛋白总抗氧化能力(1.02±0.14)U/μg蛋白和腹主动脉内皮依赖性舒张反应(66.2±4.6)%均显著低于WKY[分别为(51.6±5.8),(2.8±0.3)U/μgpro和81.0%±2.7%);而心、肾及主动脉中黄嘌呤氧化酶表达均显著高于WKY大鼠(P<0.05)。黄嘌呤氧化酶抑制剂Oxy能明显降低黄嘌呤氧化酶mRNA表达(降低31.6%),且改善腹主动脉内皮依赖型舒张反应(提高20.2%),但对eNOS表达则无显著影响。结论结果提示SHR中存在内皮功能障碍和氧化应激状态,黄嘌呤氧化酶参与了SHR内皮功能障碍。     

黄嘌呤氧化酶对血管内皮功能障碍的影响

目的 考察黄嘌呤氧化酶(xanthine oxidase)在自发性高血压大鼠(SHR)血管舒缩及内皮功能障碍中的作用.方法 采用尾套法测定SHR和正常大鼠(WKY)血压;Greiss反应测定血清一氧化氮分泌量;FRAP(ferric reduction ability power)法测定主动脉蛋白总抗氧化能力;RT-PCR法考察黄嘌呤氧化酶及内皮型一氧化氮合酶(eNOS)mRNA表达情况;血管环舒缩测定来评价黄嘌呤氧化酶抑制剂别嘌呤醇(oxypurinol,Oxy)对大鼠腹主动脉内皮依赖性舒张反应的影响.结果 SHR血压(191.1±5.6)显著高于WKY大鼠(140.4±5.9)mm Hg;SHR血清NO分泌量(28.4±5.4)、主动脉蛋白总抗氧化能力(1.02±0.14)U/μg蛋白和腹主动脉内皮依赖性舒张反应(66.2±4.6)%均显著低于WKY[分别为(51.6±5.8),(2.8±0.3)U/μg pro和81.0%±2.7%);而心、肾及主动脉中黄嘌呤氧化酶表达均显著高于WKY大鼠(P＜0.05).黄嘌呤氧化酶抑制剂Oxy能明显降低黄嘌呤氧化酶mRNA表达(降低31.6%),且改善腹主动脉内皮依赖型舒张反应(提高20.2%),但对eNOS表达则无显著影响.结论 结果提示SHR中存在内皮功能障碍和氧化应激状态,黄嘌呤氧化酶参与了SHR内皮功能障碍.     

一氧化氮对自发性高血压大鼠血管内皮功能的作用

目的　探讨自发性高血压大鼠 (SHR)内皮舒张功能不全的发生机制。方法　采用体外灌注的方法测定大鼠胸主动脉环对不同浓度乙酰胆碱的舒张反应变化 ,并测定血清中NO-3浓度和动脉组织中环鸟苷酸水平。结果　与魏 凯二氏大鼠 (WKY)比较 ,SHR胸主动脉环对乙酰胆碱的舒张反应明显减弱。左旋硝基精氨酸 (L NNA)可明显抑制大鼠胸主动脉环对乙酰胆碱的舒张反应 ,但并不能消除SHR和WKY对乙酰胆碱舒张反应之间的差异。与WKY比较 ,SHR血中NO-3水平明显降低 (P<0 .0 1) ,动脉组织中环鸟苷酸含量降低 (P<0 .0 1)。结论　SHR内皮依赖的血管舒张功能减低 ;一氧化氮 (NO)的生成或释放不足可能直接参与了SHR血管内皮依赖的舒张功能不全。     

Increased expression of vascular endothelial growth factor and capillary density in hearts of spontaneously hypertensive rats

OBJECTIVE: The role of VEGF in vascular remodeling of target organs exposed to chronic hypertension is poorly understood. The authors compared capillary density (CD), capillary-to-fiber ratio (C/F), and VEGF mRNA expression in the hearts (left ventricle [LV]), and skeletal muscles (soleus and anterior tibialis [AT]) of 18-week-old male spontaneously hypertensive rats (SHR) and age-matched male Wistar-Kyoto (WKY) and Sprague-Dawley (SD) rats. METHODS: CD or C/F in LV, soleus, and AT of SHR, WKY, and SD rats was determined by analysis of randomly acquired digital images of cryosections stained with FITC-conjugated GS-I lectin. VEGF mRNA expressions in the tissues were determined by Northern blot. RESULTS: VEGF mRNA expressions in LV of SHR were 3.84- and 5.05-fold higher, compared to SD and WKY rats, respectively (n = 6; p < .01). There were no significant differences in VEGF mRNA expression in soleus or AT among SHR, WKY, and SD rats (p > .05). CD in LV of SHR (4975 +/- 167) was significantly higher than WKY or SD rats, 4151 +/- 169 and 3807 +/- 187 mm(-2), respectively (p < .05). In LV of SHR, C/F increased (35%) more significantly than CD (increased 20%), compared to WKY rats. CD, or C/F in soleus or AT of SHR was similar to that observed in WKY or 8D rats. CONCLUSIONS: VEGF expression, CD, and C/F in the heart (LV) of SHR are significantly increased, compared to WKY and SD rats. The data are consistent with the possibility that VEGF may contribute to capillary growth as a compensatory response to hypertension.     

Increased oxidative stress impairs endothelial modulation of contractions in arteries from spontaneously hypertensive rats

OBJECTIVES: The endothelium modulates vascular contractions. We investigated the effects of oxidative stress on endothelial modulation of contractions in hypertension. METHODS: Changes in isometric tension of femoral arterial rings from spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats were recorded. RESULTS: The contractile response to norepinephrine of arteries with endothelium was greater in SHR than in WKY rats (P < 0.0001). Endothelium removal augmented the norepinephrine-induced contraction (P < 0.05). The augmentation was more pronounced in WKY than in SHR, which resulted in comparable contraction of arteries without endothelium in both strains. Nomega-nitro-L-arginine methyl ester (100 micromol/l) mimicked the effect of endothelium removal. Production of nitric oxide (NO, assessed by measuring nitrite/nitrate concentrations) during the contraction was not different between SHR and WKY. Vitamin C suppressed the contraction of arteries with endothelium from SHR but not from WKY (P < 0.05). Diphenyleneiodonium and apocynin, inhibitors of nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate (NADH/NADPH) oxidase, attenuated the contraction of arteries with endothelium from SHR (P < 0.001) but not WKY, but did not affect contractions induced by serotonin. Superoxide generated by xanthine oxidase/hypoxanthine enhanced the norepinephrine-induced contraction of arteries with endothelium from WKY (P < 0.0001), and this effect was reversed by vitamin C. CONCLUSIONS: In rat femoral arteries, NO released from the endothelium modulates vascular contraction. In SHR, production of superoxide by NADH/NADPH oxidase, which may be activated by norepinephrine, is enhanced, resulting in the inactivation of NO and impairment of endothelial modulation of vascular contractions. Vascular oxidative stress may contribute to the altered circulation in hypertension by impairing endothelial modulation of vascular contractions.     

通心络对糖尿病并发动脉粥样硬化大鼠心脏功能的影响

目的:评价通心络对于糖尿病并发动脉粥样硬化大鼠的血管内皮功能和心脏保护作用。方法:取25只雄性Wistar大鼠,其中20只经尾静脉注射链脲佐菌素和高脂饮食制备糖尿病并发动脉粥样硬化大鼠模型。成模后随机分为单纯模型组和通心络组,单纯模型组给予生理盐水灌胃6周,通心洛组给予通心络超微粉水溶液1 g/(kg·d)灌胃治疗6周,另外5只大鼠给予普通饲料作为正常组。治疗结束后行心脏超声检查,并检测血管性假血友病因子(v WF)和内皮素-1(ET-1),同时取左室心肌组织进行病理学检查。结果:1超声结果显示,与正常组相比,单纯模型组和通心络组大鼠的室间隔厚度(IVST)、左室后壁厚度(LVPWT)、左室舒张末内径(LVEDD)、左室收缩末内径(LVESD)和左室质量指数(LVMI)显著增大(均P<0.05);通心络组的上述指标比单纯模型组均显著降低(P<0.05)。2生化检验结果显示单纯模型组的v WF和ET-1比正常组显著增加(均P<0.05),通心络组的v WF和ET-1水平低于单纯模型组(均P<0.05),略高于正常组(无统计学差异)。3病理学结果示与正常组相比,单纯模型组和通心络组都出现间质水肿、心肌坏死;但通心络组病变程度比模型组轻。结论:糖尿病并发动脉粥样硬化大鼠存在内皮损伤,心室重构。通心络可以抑制心室重构,保护心肌组织,改善血管内皮功能。     

血管内皮生长因子与自发性高血压大鼠血管重构的关系

目的探讨血管内皮生长因子与血管重构的关系。方法12只13周龄雄性自发性高血压大鼠(SHR组)作为观察组,12只同周龄雄性WKY大鼠作为正常血压对照组(WKY组)。分别于实验的第4、8周末每组处死大鼠各6只。采用酶联免疫吸附法测定血浆血管内皮生长因子浓度;放射免疫法测定颈动脉血管紧张素Ⅱ浓度;病理图象管理系统测定颈动脉管腔横截面积、内弹力层围绕面积、外弹力层围绕面积,评价内膜和中膜增生程度;免疫组织化学法检测颈动脉血管内皮生长因子蛋白表达。结果与WKY组比较,SHR组血浆血管内皮生长因子浓度明显下降,颈动脉血管内皮生长因子蛋白表达明显减弱,颈动脉血管紧张素Ⅱ浓度却显著升高(P<0.01),8周末这一作用更加显著(P<0.01);SHR组内膜增生较WKY组明显,中膜面积显著增大(P<0.01)。结论在血管重构过程中,血管内皮生长因子水平下降,提示血管内皮生长因子可能具有改善血管重构的作用。     

Modulation of endothelin-1 coronary vasoconstriction in spontaneously hypertensive rats by the nitric oxide system

To determine whether nitric oxide contributes to the augmented vasoconstrictive response to endothelin-1 (ET-1) in coronary vessels of hypertensive hearts, and also whether l-arginine administration can inhibit the augmented response to ET-1, we designed experiments to measure coronary perfusion resistance in isolated hearts of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) with or without l-arginine administration (0.5 g/L) for 2 weeks. The hearts were paced at a constant rate and perfused by the Langendorff technique at constant pressure (75 mm Hg). Perfusion flow and pressure were monitored, and coronary vascular resistance (CVR) was calculated. ET-1 infusion elicited dose-dependent increases in CVR in both WKY and SHR. At an ET-1 concentration of 1.5 × 10⁻⁹ mol/L, the response was significantly greater in SHR. In L-NAME–treated WKY and SHR, responses to ET-1 were augmented, compared with those of nontreated rats, and this augmentation was greater in WKY. l-arginine administration reduced the CVR response to ET-1 in SHR, whereas it did not change responses to ET-1 in WKY. These findings suggest that the augmented vasoconstriction of the coronary artery induced by ET-1 in hypertensive hearts was due to a reduction in nitric oxide release in coronary vessels and that l-arginine can partially inhibit the vasoconstrictive response of the coronary artery.     

Exaggerated hypotensive effect of vascular endothelial growth factor in spontaneously hypertensive rats

Vascular endothelial growth factor (VEGF) induces hypotension in normotensive subjects, which is considered to be a major side effect for treatment of ischemic diseases. However, the hypotensive effect of VEGF has not been investigated in the setting of hypertension. This study determined effects of VEGF on hemodynamics, pharmacokinetics, and release of NO and prostaglandin I2 (PGI2) in vivo and on vasorelaxation of mesentery artery rings in vitro in spontaneously hypertensive rats (SHR) compared with Wistar-Kyoto rats (WKY). Intravenous infusion of VEGF for 2 hours produced a dose-related decrease in arterial pressure, which was enhanced in conscious SHR compared with WKY (P<0.01), and an increase in heart rate in WKY but not in SHR. In response to similar doses of VEGF, compared with WKY, SHR had a higher plasma VEGF level and lower VEGF clearance (P<0.01). Circulating NO and PGI2 levels after VEGF administration were not increased in SHR versus WKY, and VEGF-induced vasorelaxation was blunted in SHR versus WKY in vitro, suggesting endothelial dysfunction in SHR. One-week VEGF infusion also caused greater hypotension (P<0.05) in the absence of tachycardia in SHR compared with WKY controls. Thus, despite blunted vasorelaxation in vitro because of endothelial dysfunction, SHR exhibited exaggerated hypotension without tachycardia in response to VEGF, which was independent of NO and PGI2. The exaggerated hypotensive response to VEGF in SHR may be owing to impaired baroreflex function and reduced VEGF clearance. The data may also suggest that more caution should be taken when VEGF is administered in patients with hypertension.     

Comparative effects of candesartan and enalapril on augmented vasoconstrictive responses to endothelin-1 in coronary vessels of spontaneously hypertensive rats

BACKGROUND: The aim of this study was to compare the effect of angiotensin type-1 receptor blockade (ARB) on augmented vasoconstrictive response to endothelin-1 (ET-1) in coronary vessels of hypertensive hearts with angiotensin converting enzyme (ACE) inhibitor, candesartan cilexetil (CAN) or enalapril was administered for 3 weeks in spontaneously hypertensive rats (SHR). METHODS: We used SHR (9 to 12 weeks old, n = 18) and Wistar-Kyoto (WKY) rats (n = 6). Systolic blood pressure was measured once a week. Spontaneously hypertensive rats were divided into three groups. Enalapril malate (10 mg/day) or CAN (10 mg/day) was administered orally in each of six SHR in each group receiving treatment for 3 weeks. The control group (n = 6) received no treatment. At the end of this experiment, the hearts were isolated. Isolated hearts mounted on a Langendorff apparatus after weighing were then perfused with modified Krebs-Henseleit buffer at constant pressure (75 mm Hg). The coronary perfusion pressure and coronary flow were measured during perfusion of isolated hearts. Coronary vascular resistance (CVR; mm Hg/mL/min/100 g) was calculated. RESULTS: The ET-1 elicited increases in CVR dose-dependently in both normotensive and hypertensive rat hearts. However, the responses were significantly greater in SHR than in WKY rat. Chronic treatment with enalapril or candesartan inhibited the development of hypertension and cardiac hypertrophy equally in SHR. Augmented vasoconstrictive responses to ET-1 were significantly reduced in treated SHR. There was no difference in these effects between enalapril and candesartan. CONCLUSION: These findings suggest that both ACE inhibitors and ARB can equally inhibit augmented coronary vascular response to ET-1 in hypertensive hearts.     

苯那普利对自发性高血压大鼠血管内皮舒张功能的改善作用

目的 :探讨苯那普利能否改善自发性高血压大鼠 (SHR)血管内皮舒张功能。　　方法 :采用体外灌注法测定苯那普利治疗组 (治疗组 )及对照组胸主动脉环对乙酰胆碱的舒张反应 ,并比较两组血清中 NO3- 浓度、动脉组织中环鸟苷酸 (c GMP)水平。　　结果 :与对照组比较 ,治疗组胸主动脉环对乙酰胆碱的最大舒张反应明显增强 (P<0 .0 1)。左旋硝基精氨酸 (L-NNA)几乎完全消除了治疗组和对照组舒张反应之间的差异。治疗组血清 NO3-浓度和动脉组织 c GMP的含量均明显增加 (P均 <0 .0 1)。　　结论 :苯那普利长期治疗可明显改善 SHR血管内皮舒张功能 ,其机制可能是增加了内皮一氧化氮的合成或释放