红花-甘草配伍对寒凝血瘀模型大鼠血浆及脑组织中腺苷酸及能荷的影响

目的：研究红花-甘草配伍对寒凝血瘀模型大鼠血浆及脑组织中三磷酸腺苷（ATP）、二磷酸腺苷（ADP）、一磷酸腺苷（AMP）及能荷（EC）水平的影响,从能量代谢角度探讨该配伍对寒凝血瘀证的影响。方法：采用冷水冰浴方法成功建立寒凝血瘀证SD大鼠模型,将造模成功大鼠随机分为4组,即模型对照组、红花组、甘草组、红花-甘草组,另设正常对照组。造模成功后,给药组灌胃相应的药物,剂量为20 g·kg^-1,模型对照组和正常对照组给予等容积的纯净水,各组均连续灌胃15 d,检测大鼠血浆及脑组织中3种腺苷酸的含量并计算能荷值。结果：与正常对照组相比,模型对照组ATP、ADP的含量及EC值均显著降低（P<0.01）,AMP的含量降低不明显。与模型对照组相比,各给药组ATP、ADP的含量及EC值均显著升高,红花-甘草组改善上述指标的作用强于单药组,差异有显著性（P<0.05）。结论：红花和甘草均可改善寒凝血瘀模型大鼠的能量代谢,促进机体对能量物质的利用,红花-甘草配伍对改善寒凝血瘀证能量代谢显示出更佳的疗效。     

阿托伐他汀对自发性高血压大鼠肠系膜动脉内皮功能障碍的改善作用研究

目的:研究阿托伐他汀对自发性高血压大鼠(SHRs)肠系膜动脉内皮功能障碍的改善作用。方法:取京都种维斯特大鼠(WKYs)为对照组(生理盐水),另取SHRs分为模型组(生理盐水)和阿托伐他汀组(10mg.kg-1.d-1),每组8只,灌胃给予相应药物,连续8周,处死后采用敏感的肌张力描记技术测定各组大鼠离体肠系膜动脉环对KCl、苯肾上腺素(PE)、乙酰胆碱(Ach)引起的收缩/舒张反应的张力变化,以及抗坏血酸(100μmol.L-1)和一氧化氮合酶(NOS)拮抗药N-硝基-L-精氨酸甲酯(L-NAME)(100μmol.L-1)对Ach舒张反应的影响。结果:与对照组比较,模型组大鼠动脉环对KCl和PE引起的最大收缩反应明显增强(P<0.01),对Ach的最大舒张反应明显减弱(P<0.01);而阿托伐他汀组可对抗模型组的上述作用。L-NAME可抑制对照组Ach的舒张反应,但不能影响模型组,阿托伐他汀治疗后恢复了L-NAME对Ach舒张反应的抑制作用。抗坏血酸可促进模型组Ach的舒张反应,但不能影响对照组,阿托伐他汀作用后抗坏血酸的作用消失。结论:阿托伐他汀可以通过提高抗氧化能力和/或增加NO的利用度来改善自发性高血压大鼠肠系膜动脉的内皮功能障碍。     

黄杨宁及其改构化合物对大鼠离体血管环舒张作用的比较

目的:比较黄杨宁(CVB-D)及其结构改造衍生化合物(CVB-D1,CVB-D2和CVB-D3)对大鼠胸主动脉的舒张作用。方法:采用氯化钾或去氧肾上腺素预收缩血管,观察CVB-D及其改构化合物对血管的舒张作用。将血管与6×10-4mol.L-1CVB-D或CVB-D3预孵育,观察二者对氯化钾或去氧肾上腺素收缩血管作用的影响。结果:在1×10-5～6×10-4mol.L-1浓度范围内,CVB-D对KCl或PE预收缩血管环的舒张作用呈剂量依赖性,CVB-D1舒张预收缩血管的作用较弱,CVB-D2无舒张预收缩血管的作用,CVB-D3舒张预收缩血管的最大效应强于CVB-D;CVB-D和CVB-D3对内皮完整血管环的舒张作用均强于去内皮血管环;CVB-D和CVB-D3与血管预孵育均可抑制氯化钾或去氧肾上腺素引起的血管收缩,且CVB-D3的抑制作用强于CVB-D。结论:CVB-D与CVB-D3具有类似的血管舒张作用,但后者的最大效应强于前者。     

缝隙连接在苯肾上腺素缩血管中的作用

目的　探讨缝隙连接 (GJ)在苯肾上腺素 (PE)缩血管中的作用。方法　通过大鼠离体肠系膜动脉环 (superiormesentericarterialrings,MARs)试验 ,观察GJ阻断剂Hep tanol预处理对PE引起的去内皮和完整内皮MARs收缩及其量效曲线的影响。结果　Heptanol预处理可明显抑制 1 0× 10 - 7mol·L- 1PE的缩血管作用 ,并呈剂量依赖关系。 3 0× 10 - 5 mol·L- 1Heptanol抑制百分率分别为 11 70 %±3 2 5% (去内皮组 )和 15 2 4%± 7 87% (完整内皮组 ) ;3 0× 10 - 4mol·L- 1Heptanol预处理 ,抑制百分率分别为3 6 3 6%± 11 54% (去内皮组 )和 3 8 85%± 13 0 3 % (完整内皮组 ) ;同浓度Heptanol对PE致去内皮和完整内皮MAR收缩的抑制作用差异无显著性。 3 0× 10 - 5 ,1 0× 10 - 4,3 0× 10 - 4mol·L- 1Heptanol使PE的量效曲线右移 ,最大效应 (Emax)不变。结论　GJ参与介导苯肾上腺素的缩血管作用 ,GJ阻断剂Heptanol对PE缩血管的抑制作用无明显内皮依赖性 ,具易逆性特点     

阿托品对大鼠肠系膜动脉的舒张作用及机制

目的研究阿托品的扩血管作用及机制。方法以大鼠肠系膜动脉为标本，考察阿托品对去甲肾上腺素(NE)预收缩血管的舒张作用以及血管内皮细胞、血管平滑肌在该效应中的作用。结果阿托品能显著舒张NE预收缩的完整内皮血管，去内皮后该作用明显降低。L-N^ω-硝基精氨酸甲酯、吲哚美辛、普萘洛尔及格列本脲对阿托品的舒张作用无明显影响。阿托品对KCl的量效曲线及咖啡因缩血管作用均无明显影响，但能浓度依赖性地抑制NE诱导的内钙释放以及经受体操纵性钙通道的外钙内流。结论阿托品有明显的扩血管作用，其通过抑制受体介导的外钙内流和内钙释放而舒张血管。     

儿茶酚抑素对大鼠离体血管环张力的影响

目的研究儿茶酚抑素(CST)对大鼠离体血管环的效应及其可能的机制。方法记录苯肾上腺素(PE)预收缩的大鼠离体胸主动脉环张力变化,观察不同浓度CST的作用效果以及应用L-硝基-精氨酸甲酯(L-NAME)抑制一氧化氮(NO)生成后的作用效果的变化。结果①PE(10-9～10-5mmol/L)对大鼠离体血管环有浓度依赖性的收缩作用;②CST在10-8～10-4mol/L浓度范围内对PE(10-6mmol/L)引起的血管收缩有浓度依赖性的舒张作用,其舒张作用较同等浓度的乙酰胆碱(Ach)和硝普钠(SNP)均弱;③用L-NAME(10-4mol/L)预处理后,CST的作用明显减弱。结论 CST对PE诱发的血管收缩有浓度依赖性的舒张作用,血管内皮释放的NO可能是CST的作用途径之一。     

维药唇香草醇提物对大鼠离体胸主动脉血管环的舒张作用

目的:研究唇香草醇提物(EEZ)对大鼠离体胸主动脉血管环的舒张作用。方法:制备大鼠离体胸主动脉血管环。试验设内皮完整组与内皮去除组,以去氧肾上腺素(PE)预收缩血管环后逐步累积加入100、300、500、700、900、1 100 mg/L EEZ,绘制浓度-张力曲线并计算最大舒张率(Emax)、半数有效浓度(EC50)。试验只设血管环内皮去除组,在无钙或无钙高钾液中以EC50的EEZ预处理血管环后逐步分别累积加入0.4、0.8、1.2、1.6、2.0、2.4 mmol/L Ca Cl2,绘制钙浓度-张力曲线;以EC50的EEZ预处理血管环后加入1μmol/L PE记录收缩张力并计算血管收缩百分率。结果:EEZ对PE预收缩的血管环具有浓度依赖性和平滑肌依赖性的舒张作用;内皮完整组与内皮去除组Emax分别为(58.18±16.23)%与(73.54±17.21)%,EEZ的EC50为773.27 mg/L。在无钙高钾液中,EEZ可以明显引起钙离子收缩曲线右移;在无钙液中,EEZ对PE引起的血管收缩具有抑制作用。结论:EEZ具有血管舒张作用,其机制可能是通过抑制电压依赖性钙通道(VDCCs)的方式来抑制外钙内流和胞质内钙释放,从而干扰胞质内钙离子平衡。     

盐酸关附甲素对大鼠血管舒缩功能的影响及其机制

目的研究盐酸关附甲素(guanfu base-A,GFA)对大鼠离体胸主动脉舒缩功能的影响,并探讨其可能机制。方法将SD大鼠胸主动脉分离并制成血管环,分成内皮完整组和去内皮组,采用离体血管环实验,观察GFA对基础状态,氯化钾(KCl)预收缩及苯肾上腺素(phenylephrine,PE)预收缩的血管舒张功能的影响,并结合不同抑制剂及无钙液处理,探讨其舒张血管的可能机制。结果累积浓度的GFA(10-8～10-4mol·L-1)对基础状态或KCl预收缩的有无内皮的血管环的张力均无明显影响(P>0.05);对PE(10-6mol·L-1)预收缩内皮完整的血管有浓度依赖性舒张作用,而与PE预收缩的去内皮组相比,从10-7mol·L-1开始差异有显著性(P<0.01)。一氧化氮合酶抑制剂L-NAME、鸟苷酸环化酶抑制剂亚甲蓝及环氧合酶抑制剂吲哚美辛孵育后,均能明显抑制GFA的扩血管作用(P<0.01);经无钙液及GFA处理后,胸主动脉对PE的反应性降低(P<0.01)。结论 GFA对大鼠胸主动脉的舒张作用主要通过两种途径:内皮依赖性舒张作用的机制主要与NO-GC-cGMP途径及激活环氧合酶有关;非内皮依赖性舒张机制主要与抑制内钙释放有关,与门控钙通道引起的外钙内流无关。     

血管紧张素Ⅱ对不同年龄大鼠心脏α_1肾上腺素受体介导正性变力效应的影响

目的研究在不同年龄组大鼠,激动血管紧张素Ⅱ受体(ATR)对α1肾上腺素受体(α1-AR)介导的心肌正性变力效应的影响是否不同。方法测定Wistar大鼠离体左心房收缩效应。结果在3.5月龄大鼠离体左心房,血管紧张素Ⅱ(AngⅡ)0.001~30μmol.L-1未能诱导出正性变力效应。在3.5,12,18和24月龄组大鼠,苯肾上腺素(PE)引起左心房浓度依赖性正性变力效应。与3.5月龄大鼠相比,12月龄大鼠的PE累积浓度-收缩效应曲线无明显变化,18和24月龄大鼠的最大收缩反应(Rmax)及pD2值均明显下降。AngⅡ100nmol.L-1预处理30min对3.5和12月龄大鼠左心房的PE累积浓度-收缩效应曲线没有明显影响,但使18和24月龄大鼠的PE累积浓度-收缩效应曲线左移,Rmax及pD2增大。结论AngⅡ不能诱导大鼠心肌正性变力效应。但随着年龄增长,心肌α1-AR反应性降低时,激动ATR可增强α1-AR介导的正性变力效应。     

去窦弓神经大鼠的胸主动脉重构

目的　观察大鼠去窦弓神经 (SAD)后由于血压不稳定而引起的血管重构。方法　 10wk大鼠行SAD或Sham ,术后 16周用离体动脉环实验测定SAD和相应Sham组大鼠胸主动脉对去甲肾上腺素 (NE)和氯化乙酰胆碱 (Ach)的收缩和舒张反应 ;用组织病理学和计算机图像分析技术对大鼠的胸主动脉连续切片进行观察和比较。结果　与Sham组相比 ,SAD大鼠离体胸主动脉环对NE的收缩反应增强 ,对Ach的舒张反应减弱 ;SAD组大鼠胸主动脉的结构改变主要以血管中层平滑肌细胞肥大和基质扩充为主。结论　大鼠去窦弓神经后单纯血压不稳定可引起血管重构     

Heat stress alters G-protein coupled receptor-mediated function and endothelium-dependent relaxation in rat mesenteric artery

Heat stress has been demonstrated to have strong cardiovascular effects. However, the underlying mechanism-mediated cardiovascular effects are still not fully understood. The present study was designed to examine if heat stress alters vascular G-protein coupled receptor-mediated vasomotion and endothelium function in rat mesenteric artery. Rats were divided into two groups, heat stress rats and control. The G-protein coupled receptors of endothelin type B (ETB) receptor-, endothelin type A (ETA) receptor-, 5-hydroxytryptamine (5-HT) receptor-, calcitonin gene-related peptide (CGRP) receptor-, alpha-adrenoceptor-mediated vosoactivity and endothelium-dependent relaxation on rat mesenteric artery ring segments were monitored by a myograph system. The plasma level of CGRP was determined by radioimmunological assay. Compared with control arterial segments, the contractile response curves of sarafotoxin 6c, a selective ETB receptor agonist and 5-HT in the arterial segments from heat stress rats were shifted towards left. An increased maximum contraction (Emax) induced by sarafotoxin 6c, but not 5-HT, was seen in the arterial segments from heat stress rats. CGRP-induced relaxation in endothelium-denuded arterial segments from heat stress rats was enhanced. The relaxation in endothelium-intact arterial segments induced by acetylcholine was significantly decreased in heat stress rats. In addition, the plasma concentration of CGRP was increased in heat stress rats. The endothelium-dependent relaxation was characterized and shown there was a decrease in nitric oxide and endothelium-derived hyperpolarizing factor-mediated relaxation in the arterial segments from heat stress rats. In conclusion, heat stress induces an enhanced vascular endothelin ETB-, 5-HT-receptors-mediated contraction, an enhanced CGRP-receptor-induced relaxation and damage to endothelium-dependent relaxation.     

The effect of morphine in rat small mesenteric arteries

We investigated the effect of morphine in phenylephrine (PE)- or KCl-precontracted rat small mesenteric arteries. Morphine (10(-6)-10(-4) M) administration caused concentration-dependent relaxation responses in small mesenteric arteries precontracted by PE or KCl. Removal of endothelium did not significantly alter the relaxation responses to morphine. The relaxant responses to morphine were partially inhibited by pre-treatment of tissues with naloxone (NAL, 10(-5) M) for 20 min. The inhibitory effect of NAL on relaxant responses to morphine in PE- or KCl-precontracted arteries did not differ significantly between endothelium-intact and endothelium-denuded preparations. Incubation of endothelium-intact or endothelium-denuded arterial segments with NOS inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME, 10(-4) M) or cyclooxygenase (COX) inhibitor indomethacin (10(-5) M) or histamine H(1)-receptor blocker diphenhydramine (10(-6) M), for 20 min did not inhibit the relaxation responses to morphine. Small mesenteric arterial segment contractions induced by stepwise addition of calcium to high KCl solution with no calcium were almost completely inhibited by morphine. These findings suggested that morphine-induced relaxation responses in isolated rat small mesenteric arteries were neither dependent on endothelium nor blocked by NOS or COX inhibition but they rather seem to depend on an interaction of morphine with calcium influx pathways.     

红景天苷对慢性心力衰竭大鼠肠系膜动脉舒缩作用的影响

目的探讨红景天苷（Salidroside,SAL）对慢性心力衰竭（心衰）大鼠离体肠系膜动脉舒缩作用的影响。方法将20只大鼠随机分为心衰组、假手术组,每组10只。心衰组采用腹主动脉缩窄术制备压力超负荷心衰大鼠模型,假手术组制备方法同心衰组,但腹主动脉只穿过线而不进行缩窄。术后16周,取假手术组（n=8）和心衰组（n=5）大鼠处死后制备肠系膜动脉环,予去氧肾上腺素（PE）预收缩,以不同累积浓度的SAL（10^-8、10^-7、10^-6、10^-5、10^-4mol/L）直接作用预收缩的肠系膜动脉环,应用DMT微血管张力测定仪测定比较两组肠系膜动脉环张力。结果SAL对PE预收缩的心衰组大鼠肠系膜动脉环产生浓度依赖性舒张作用,与假手术组比较,除10-8mol/L之外各浓度作用下差异均有统计学意义（P〈0.01）;心衰组SAL诱导的最大舒张反应（Emax）和半数有效浓度（EC50）均高于假手术组（P〈0.05,P〈0.01）。结论 SAL对心衰大鼠动脉在具备血管收缩功能的同时还具有浓度依赖性舒张效应,这种调节能力对于临床休克状态下靶器官功能的保护有重要意义。     

高血压左室肥厚大鼠血管内皮的去留对NE和Ach反应的研究

间硝地平(m-Nif)和硝苯地平(Nif)在预防和逆转肾型高血压大鼠左室肥厚(LVH)的同时可通过影响血管平滑肌功能和血管内皮功能来降低血管对NE的反应性.抑制NE收缩反应:LVH组ED_50在内皮完整和去内皮时分别为101±39nmol·L~(-1),360±72nmol·L~(-1),NE-比率为1.80,各药物组的ED_(50)均增大,NE-比率降低.LVH大鼠血管对Ach的依内皮性舒张反应降低,m-Nif和Nif对Ach依内皮舒张反应没有明显影响.     

Involvement of beta 2-adrenoceptors in the regional haemodynamic responses to bradykinin in conscious rats.

1. Bradykinin can release neuronal calcitonin gene-related peptide (CGRP) and adrenal medullary catecholamines, both of which could contribute to its cardiovascular effects in vivo. Therefore, in the main experiment, regional haemodynamic responses to bolus injections of bradykinin (3 nmol kg-1, i.v.) were assessed in the same chronically-instrumented, conscious, Long Evans rats in the absence and in the presence of human alpha-CGRP [8-37] or ICI 118551, antagonists of CGRP1-receptors and beta 2-adrenoceptors, respectively. The selected doses of these antagonists caused specific inhibition of responses mediated by exogenous human alpha-CGRP and beta 2-adrenoceptor agonists, respectively. 2. Bradykinin administered alone as an i.v. bolus had a slight pressor effect accompanied by a marked tachycardia. There were early (at about 30 s) increases in flow and conductance in the mesenteric vascular bed, and delayed (at about 90 s), but qualitatively similar, changes in the hindquarters vascular bed. There were only slight increases in flow and conductance in the renal vascular bed. 3. Human alpha-CGRP [8-37] had no statistically significant effects on the responses to bolus doses of bradykinin. However, in the presence of ICI 118551, the pressor effect of bradykinin was significantly enhanced while its tachycardic effect was significantly suppressed. The hindquarters vasodilator effect of bradykinin was converted to a vasoconstriction and there was a slight renal vasoconstriction, but the mesenteric vasodilator effect of bradykinin was unchanged by ICI 118551. 4. In subsidiary experiments, in other animals, it was found that infusion of bradykinin (36 nmol kg-1 min-1) elicited a pattern of haemodynamic responses similar to that seen with bolus injections and, as in the latter case, the hindquarters hyperaemic vasodilation was inhibited by ICI 118551. In the presence of mecamylamine (at a dose sufficient to block reflex heart rate responses to rises or falls in arterial blood pressure) bolus injection or infusion of bradykinin still elicited increases in renal, mesenteric and hindquarters blood flow. However, in additional experiments in adrenal demedullated rats (n = 4) the hindquarters hyperaemic effect of bradykinin was absent, although the mesenteric hyperaemic effect remained. 5. The results indicate that the increase in hindquarters blood flow following administration of bradykinin in vivo is largely due to activation of beta 2-adrenoceptors by catecholamines released subsequent to direct stimulation of the adrenal medulla by the peptide. However, the bradykinin-induced increase in mesenteric blood flow does not depend on this mechanism.     

Age-dependent changes in blood pressure and arterial reactivity in obese Zucker rats

The purpose of the present investigation was to determine whether there is an association between changes in arterial reactivity to vasoactive agents and the development of hypertension in obese Zucker rats. At 20 weeks of age, obese rats were mildly hypotensive compared to their lean littermate controls. Maximum contractile responses of endothelium-intact mesenteric arteries from these rats to noradrenaline, endothelin-1 and KCl were depressed, although there was no change in relaxation to acetylcholine. By 32 weeks of age, obese rats had developed hypertension compared to their lean littermate controls. Maximum contractile responses of mesenteric arteries from 32-week-old obese rats to noradrenaline and endothelin-1 were no longer significantly different than control, although contractile responses to KCl remained depressed. In addition, there was a small increase in sensitivity to endothelin-1, while endothelium-dependent relaxation to acetylcholine was impaired. In contrast, there were no changes in contractile responses of endothelium-intact aortas from either 20- or 32-week-old obese rats to noradrenaline, endothelin-1 or KCl, while endothelium-dependent relaxation of this artery to acetylcholine was slightly enhanced at both ages. Therefore, changes in the reactivity of the mesenteric artery but not the aorta from obese Zucker rats parallel changes in blood pressure in these animals.     

Effect of ethanol consumption on blood pressure and rat mesenteric arterial bed, aorta and carotid responsiveness

This study investigates whether chronic ethanol consumption increases blood pressure and alters vascular reactivity in different tissues. Changes in reactivity to phenylephrine and acetylcholine were investigated in the aorta, carotid artery and mesenteric arterial bed (MAB) isolated from rats pretreated with ethanol for 2 or 6 weeks. Mild hypertension was observed in chronically ethanol-treated rats, which was due to rises in both systolic and diastolic pressures. Chronic ethanol consumption increased the contractile response to phenylephrine of endothelium-intact and denuded rat aortic rings from rats pretreated with ethanol for 2 or 6 weeks. Conversely, no differences were found in acetylcholine-induced relaxation. Neither phenylephrine-induced contraction nor acetylcholine-induced relaxation were altered in the rat carotid. Six weeks' ethanol consumption enhanced the contractile response to phenylephrine of endothelium-intact, but not denuded rat MAB. On the other hand, 2 weeks' ethanol consumption did not affect phenylephrine-induced increase in perfusion pressure. Moreover, acetylcholine-induced endothelium-dependent relaxation in the MAB was reduced after treatment with ethanol for 6 weeks but not after 2 weeks. In conclusion, ethanol affects both blood pressure and vessel reactivity, but the effect on vascular reactivity may take longer to become apparent in MAB than in the aorta, and was not evident in the carotid. Moreover, we provide evidence that the effect of ethanol depends on the agonist and blood vessel studied.     

去甲肾上腺素和异丙肾上腺素对猪冠状动脉的舒张作用及机制研究

目的:研究去甲肾上腺素和异丙肾上腺素对冠状动脉环的舒张作用及其可能的作用途径。方法:采用离体实验方法,检测去甲肾上腺素和异丙肾上腺素对静息张力及氯化钾(KCl)预收缩冠状动脉的影响,研究两者对冠状动脉张力的作用及其可能的机制。结果:去甲肾上腺素和异丙肾上腺素对静息张力及KCl(40 mmol.L-1)预收缩冠状动脉环具有浓度依赖性舒张作用。去除内皮,用β受体阻断药普萘洛尔,β1受体抑制药阿替洛尔预处理后,均可明显减弱去甲肾上腺素和异丙肾上腺素诱导的舒张血管作用;用鸟苷酸环化酶抑制药亚甲蓝,一氧化氮合酶抑制药(L-NMMA),β2受体抑制药ICI-118551(10～5 mol.L-1)预处理后,血管舒张作用不能被阻断。α受体阻断药酚妥拉明预处理能增强去甲肾上腺素的舒张作用,对异丙肾上腺素引起的舒张无影响。结论:去甲肾上腺素和异丙肾上腺素是通过激活冠状动脉血管上的β受体(特别是β1受体)产生内皮依赖性的血管舒张作用,与NO-鸟苷酸环化酶途径无关。说明β肾上腺素能受体在猪冠状动脉血管平滑肌和血管内皮上有分布。