硫化氢对自发性高血压大鼠心肌重构的作用及机制研究

目的 探讨硫化氢H2S对自发性高血压大鼠（SHR）间隙连接蛋白40（Cx40）、43（Cx43）表达的调控作用,以及与心肌重构的关系。方法 取8周龄雄性SHR 16只,随机分为SHR对照组（n?=8）、SHR+ 硫氢化钠NaHS组（n?=8）;取同周龄的正常Wistar京都（WKY）雄性大鼠8只,设为WKY组。SHR+ NaHS组腹腔注射NaHS 56?μmol/（kg·d）,SHR对照组和WKY组每日腹腔注射等量生理盐水,持续8周。用分光光度计检测各组大鼠外周血和心肌组织中H2S含量;通过HE染色及Masson三色染色观察H2S对心肌的病理学改变;通过免疫组织化学检测3组大鼠心脏组织中Cx40、Cx43表达位置的变化;运用Western blotting检测3组大鼠心脏组织中Cx40、Cx43及α-平滑肌肌动蛋白（α-SMA）、骨桥蛋白（OPN）表达量的变化。结果 与WKY组大鼠比较,SHR组大鼠外周血及心肌组织中H2S含量减少（P?<0.05）,NaHS干预后SHR外周血及心肌组织中H2S含量增加（P?<0.05）;与WKY组大鼠比较,SHR组大鼠心肌纤维结构排列较为紊乱,NaHS干预后SHR心肌纤维排列较为整齐;SHR组大鼠心肌中的Cx40、Cx43表达增加且分布紊乱,SHR+NaHS组大鼠心肌中的Cx40、Cx43分布较规整;且SHR组大鼠心肌中Cx40、Cx43、α-SMA、OPN表达升高（P?<0.05）,SHR+NaHS组大鼠心肌中Cx40、Cx43、α-SMA、OPN表达降低（P?< 0.05）。结论 H2S可能通过调控Cx40、Cx43的表达来改善SHR心肌重构。     

气体分子硫化氢对自发性高血压大鼠主动脉结构重建的调节作用

目的: 研究新型气体分子硫化氢(H2S)对自发性高血压(SHR)大鼠高血压形成期主动脉几何形态和显微结构的影响并初步探讨其调节主动脉结构重建的作用机制.方法: 4周龄雄性SHR及正常血压(WKY)大鼠各自随机分为对照组、 NaHS(H2S供体)组及 PPG(H2S代谢酶抑制剂)组,5周以后,应用图像采集与分析系统对Weigert染色的胸主动脉显微形态结构做定量分析,应用免疫组织化学的方法检测细胞增殖核抗原(PCNA).结果: 9周龄SHR 对照组大鼠血压显著高于 WKY对照组大鼠[(184±12) mm Hg对(108±23) mm Hg],而SHR NaHS 组大鼠的血压[(158±12) mm Hg]显著低于SHR对照组.SHR对照组大鼠胸主动脉的血管内径、外径、中膜面积以及壁厚与内径的比均显著高于WKY对照组[血管外径(1 999±45) μm对(1 790±96) μm,内径(1 759±91) μm对(1 636±94) μm,中膜面积(0.60±0.06) μm2对(0.48±0.03) μm2,壁厚与内径的比(0.066±0.006)对 (0.060±0.004)],血管平滑肌细胞增殖指数也高于WKY对照组[(0.24± 0.06)对(0.11±0.05)].SHR NaHS组大鼠的多数血管结构指标低于SHR对照组大鼠[外径(1 864±66) μm,内径(1 634±66) μm,中膜面积 (0.53±0.06) μm2,只有壁厚内径比(0.063±0.003)与SHR对照组相比差异无显著性],血管平滑肌细胞增殖指数显著低于SHR对照组大鼠(0.151±0.028).结论: H2S是影响高血压主动脉结构重建的关键因素之一,外源性给予其供体NaHS有助于缓解自发性高血压形成期的主动脉结构重建.     

自发性高血压大鼠硫化氢/胱硫醚γ-裂解酶体系的实验观察

目的　探讨硫化氢 /胱硫醚γ 裂解酶 (H2 S/CSE)体系在自发性高血压形成及发展中的变化及重要作用。方法　 4周龄雄性正常血压大鼠 (WKY) 8只 ,作为WKY对照组 (n =8) ,自发性高血压大鼠 (SHR) 16只 ,随机分为SHR对照组 (n =8)及SHR NaHS(外源性H2 S供体 )组 (n =8) ,其中SHR NaHS组每日腹腔注射NaHS ,WKY对照组及SHR对照组注射同样剂量的生理盐水。相同条件下饲养 5周后 ,检测其血压、左心与全心重量比 ,血浆H2 S水平、胸主动脉CSEmRNA转录水平以及胸主动脉显微结构。结果　 9周龄时SHR对照组大鼠血压显著高于WKY对照组大鼠 [(184±12 )mmHgvs (10 8± 2 3)mmHg ,1mmHg =0 .133kPa],左心与全心比值大于WKY对照组[(0 85 3± 0 0 2 1)vs (0 82 6± 0 0 2 4 ) ],胸主动脉CSEmRNA转录水平及血浆H2 S水平均低于WKY对照组大鼠 [(9 3± 0 7)× 10 -8fmolvs (16 1± 1 0 )× 10 -8fmol]及 [(2 0± 9) μmol/Lvs (4 8± 13)μmol/L],而胸主动脉显微结构结果显示胸主动脉外径、中膜面积、壁厚腔径比均大于WKY对照组大鼠 [外径 (1999± 4 5 ) μmvs (1790± 96 ) μm],中膜面积 (0 6 0± 0 0 6 )mm2 vs (0 4 8± 0 0 3)mm2 ,壁厚腔径比 (0 0 6 6± 0 0 0 6 )vs (0 0 6 0± 0 0 0 4 )。给予NaHS干预     

灯盏花乙素对SHR大鼠心脑血管内皮损伤的保护作用

目的研究高血压诱导血管内皮损伤的病理机制以及灯盏花乙素(SCU)对其的保护作用。方法为研究年轻和老年自发性高血压大鼠(SHR)冠状动脉(CA)和脑基底动脉(BA)血管功能学改变,本研究采用分离14周(14W)和40周(40 W)的SHR和高血压大鼠的对照品系(WKY)的BA和CA血管环,用乙酰胆碱(ACH)为舒张剂,应用Wire Myograph血管张力分析系统测定血管环的张力变化,观察SCU对SHR大鼠心脑血管VED的保护作用。结果与WKY组比,加入ACH累计浓度后,SHR组CA/BA的EC50均升高,且40 W SHR的EC50值高于14W SHR;SCU100μM可对SHR大鼠的血管内皮损伤起到保护作用(P0.05)。结论 SCU对SHR大鼠心脑血管的内皮损伤(VED)具有一定的保护作用。     

自发性高血压大鼠内皮素不同组织分布及其意义

为探讨内皮素(ET)在自发性高血压大鼠(SHR)与正常血压大鼠(WKY)体内分布规律及其意义。本文选用SHR和WKY大鼠各10只,用放免法测定其血浆、脑组织和主动脉血管组织中内皮素含量的变化。发现SHR血浆、脑和主动脉中ET量均显著高于WKY组(P分别<0.01);WKY组脑较血管组织含量低(P<0.01),SHR组两者无显著性差异(P>0.05)。认为内皮素不同组织分布的变化可能与高血压的发生发展及并发症有关。     

同型半胱氨酸对自发性高血压大鼠脑动脉平滑肌细胞BKca的增强作用

目的 探讨同型半胱氨酸(Hcy)对自发性高血压大鼠(SHR)和Wistar大鼠脑动脉平滑肌细胞电生理特性的影响.方法 应用全细胞膜片钳记录技术观察1 mmol/L Hcy对SHR和Wistar大鼠脑动脉平滑肌细胞膜电流的作用.结果 ①SHR脑动脉平滑肌细胞外向电流幅度远大于Wistar大鼠.②1 mmol/L Hcy电压依赖性的增强SHR与Wistar大鼠脑动脉平滑肌细胞的外向电流.Hcy主要增强SHR和Wistar大鼠脑动脉平滑肌细胞0～+60 mV区间的电流幅度.Hcy增强SHR脑动脉平滑肌细胞膜电流的幅度大于Wistar大鼠,两者间有统计学差别.③1 mmol/L TEA可以有效抑制Hcy对脑动脉平滑肌细胞外向电流的增强作用,而1 mmol/L4-AP对其没有明显影响.结论 1 mmol/L Hcy能够电压依赖的增强SHR及Wistar大鼠脑动脉平滑肌细胞BK.通道电流,且SHR比Wistar大鼠增强幅度明显.     

5-LO在SHR大鼠脑动脉平滑肌细胞中的表达及意义

【摘要】 目的 探讨5脂氧合酶（5-LO）在自发性高血压大鼠(SHR)脑动脉平滑肌细胞中的表达及意义。方法 选取16周龄雄性SHR和WKY大鼠,各15只,WKY大鼠作为正常对照。采用免疫荧光法检测5-LO在脑动脉血管中的表达,透射电镜观察动脉内膜表现,ELISA检测血清及动脉5-LO表达。结果 WKY大鼠动脉内膜光滑,平滑肌细胞排列整齐无增生,SHR大鼠内皮细胞肿胀,平滑肌细胞肥大变形排列紊乱;SHR大鼠脑动脉平滑肌细胞5-LO荧光强度为（110.93±5.92）,明显强于WKY大鼠（P＜0.05）;SHR大鼠血清和脑动脉5-LO水平分别为（2671.04±30.18）ng/l和（1950.04±30.08）ng/l,明显高于WKY大鼠,差异比较有统计学意义（P＜0.05）。结论 5-LO在SHR大鼠脑动脉平滑肌细胞和血液中表达异常增高,可能在高血压脑血管损害过程中起作用。     

p-MEK1/2与原发性高血压大鼠左心室肥厚关系的研究

目的动态观察p-MEK1/2在原发性高血压大鼠(SHR)左心室表达,进一步探讨MEK1/2-ERK1/2通路在高血压左心室重构中的作用。方法对比观察各周龄SHR大鼠与WKY大鼠血压,心脏/体重比值变化;免疫组织化学方法检测左心室p-MEK1/2的表达。结果整个实验过程中,WKY血压保持在正常水平,SHR16、SHR24组动脉收缩压均明显高于同周龄WKY组(P<0.05);与同周龄WKY相比SHR24组的心脏/体重比值增加明显(P<0.05);SHR24左心室相对壁厚度明显高于SHR8和WKY24大鼠(P<0.05);WKY和SHR大鼠左心室p-MEK1/2蛋白表达量均随着周龄的增加而增加,但SHR16、SHR24明显高于同周龄WKY(P<0.05)。结论 MEK1/2-ERK1/2通路可能有促进高血压左心室心肌肥厚发展的作用。     

自发性高血压大鼠心肌重构与p38MAPK关系的研究

目的探讨高血压对心脏的影响及可能的分子机制。方法测量不同周龄Wistar-kyoto大鼠(WKY)和自发性高血压大鼠(SHR)血压值及心脏重量,显微镜测微尺观测不同周龄SHR心脏构型,透射电子显微镜观察心肌细胞的改变,免疫组化和Western-blotting方法观察p38MAPK和磷酸化p38MAPK在高血压心脏重构中表达情况。结果 8周龄开始,SHR组血压逐渐升高,并随着周龄的增加而增加(P<0.05),SHR组动脉收缩压明显高于同周龄WKY组(P<0.05)。16、24周龄SHR大鼠的心脏/体重比值明显高于4周龄SHR,同时明显高于同周龄WKY大鼠(P<0.05)。16、24周SHR组左心室壁厚度明显高于4周龄SHR也明显高于16、24周WKY大鼠(P<0.05)。SHR组,磷酸化p38在左心室肌表达随周龄的增加逐渐增加,在SHR24表达明显高于SHR4周龄组(P<0.05)。磷酸化p38在SHR组左心室表达明显高于同周龄WKY大鼠(P<0.05)。结论长期高血压可导致心脏重构,心脏重构改变随周龄增加逐渐加重,p38MAPK信号通路磷酸化可能参与了高血压心脏重构。     

P-MEK在高血压大鼠肾小动脉平滑肌细胞中的表达及意义

目的探讨高血压肾细动脉血管平滑肌细胞(VSMCs)中ERK1/2上游信号磷酸化MEK(p-MEK)的表达状态,为进一步阐明高血压状态下VSMCs功能状态改变的分子机制提供实验依据。方法将4、16、24周龄雄性自发性高血压大鼠(SHR)作为实验组,同周龄雄性Wistar大鼠(WKY)作为对照,各组5只大鼠。弹性纤维染色观察肾小动脉的结构变化,免疫组织化学分析各组动物肾小叶间动脉和入球动脉血管VSMCs中p-MEK的表达。结果 SHR肾小叶间动脉和入球动脉VSMCs增殖不明显,小叶间动脉相对内径随周龄增加逐渐减小。同级别动脉相比,SHR大鼠p-MEK阳性细胞数高于同周龄WKY大鼠。SHR组p-MEK增高的幅度高于同周龄WKY组。结论高血压状态下肾小动脉VSMCs功能状态的改变,可能与胞内MEK磷酸化活化有关。     

高血压对大鼠脑膜中动脉内皮依赖性舒张功能的影响及机制

目的:探讨自发性高血压大鼠脑膜中动脉内皮依赖性舒张功能降低的机制。方法:以WKY为对照,观察SHR大鼠脑膜中动脉环5-羟色胺预收缩后乙酰胆碱舒张性改变,考察一氧化氮途径,前列环素途径以及内皮源性超极化因子途径在SHR脑膜中动脉舒张功能的改变,反应特征表述为最大松弛百分率(Rmax)和产生一半最大松弛百分率时所需要ACh浓度的负对数(pIC50)。ANOVA Two-way和t检验分析组间差异。透射电镜法观察SHR脑膜中动脉内皮超微结构的改变。结果:WKY大鼠脑膜中动脉Rmax和pIC50分别为97%±1%和8.67±0.21,SHR Rmax和pIC50分别为39%±2%(P<0.001)和7.05±0.65(P<0.05);NO途径在WKY大鼠,Rmax和pIC50分别为53%±2%和6.89±0.33,在SHR Rmax和pIC50分别为32%±2%(P<0.001),和3.93±0.07(P<0.001);PGI2途径在WKY大鼠,Rmax和pIC50分别为8%±1%和4.58±0.30,在SHR Rmax和pIC50分别为8%±1%,(P>0.05),和4.52±0.27,(P>0.05);EDHF途径在WKY大鼠,Rmax和pIC50分别为35±5%和6.30±0.50,在SHRRmax和pIC50分别为14%±1%,(P<0.001),和3.85±0.07,(P<0.001)。电镜观察显示SHR脑膜中动脉出现部分内皮细胞脱落,内弹力膜不完整,有断裂现象。结论:NO-和EDHF-介导的舒张功能降低以及内皮超微结构受损参与导致SHR脑膜中动脉内皮依赖性舒张功能降低。     

Pathological observation of brain arteries and spontaneous aneurysms in hypertensive rats

Objective To investigate the role of hypertension in the pathogenesis of cerebral aneurysms in rats.Methods Twenty spontaneous hypertensive rats (SHR) and 10 Wistar-Kyoto rats (WKY) were included in this observational study. Animals were fed with normal diet and drinking water. No experimental modifications were undertaken in either group. They were sacrificed at one year of age, the bifurcations of the circle of Willis were dissected and longitudinal serial sections were prepared for light microscopic and transmission electron microscopic study.Results In the SHR group, 2 of the 20 rats formed an aneurysm respectively at the bifurcations of the basilar artery. As revealed by electron microscopy, injury at the bifurcation of the artery first occurred on the steeper side of the intimal pad. Furthermore, loss of endothelial cells, small depressions on the intima, disruptive internal elastic lamina and lymphocytes or red blood cells infiltration were noted at the steeper side of the intimal pad. No significant changes were observed in WKY group.Conclusions Cerebral aneurysms can form spontaneously in SHR without ligation of the common carotid artery and without a diet containing β-aminoproprionitrile. Long-standing systemic arterial hypertension is one of the etiological factors that contributes to aneurysm formation in SHR rats.     

不同遗传背景及增龄对大鼠高血压胰岛素抵抗相关基因表达谱的影响

目的：探讨不同遗传背景以及增龄对大鼠高血压胰岛素抵抗相关基因表达谱的影响,筛选高血压胰岛素抵抗相关基因.方法：以自发性高血压（SHR）大鼠和Wistar-Kyoto（WKY）大鼠为动物模型,用S4000点基因表达谱芯片分别检测不同遗传背景（14wk SHR大鼠和14wk WKY大鼠）的大鼠肾组织差异表达基因、增龄（SHR大鼠从5wk增龄至14wk）对SHR大鼠肾组织基因表达谱的影响,并从中随机选取2个差异表达基因,用RT-PCR方法进行验证.结果：①SHR大鼠增龄后肾组织中差异表达基因209个;14wk SHR大鼠与14wk WKY大鼠相比较肾组织差异表达基因有166个;②根据SHR大鼠增龄及不同遗传背景大鼠肾组织2种基因表达谱芯片检测结果显示,两者共同差异表达基因11个,其中免疫相关基因2个、代谢相关基因4个、其他类型基因5个.结论：代谢、免疫相关基因表达差异可能在高血压胰岛素抵抗发病中起重要作用.     

Endothelium-dependent inhibition of the contractile response is decreased in aorta from aged and spontaneously hypertensive rats

BACKGROUND: Stimulation of vascular 5-hydroxytryptamine-2C (5-HT(2c)) receptors produces contraction in rat aorta. We investigated the effect of aging on endothelium-dependent inhibition of contractile responses in thoracic aorta from normotensive Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR). METHODS: Endothelium-intact and denuded aortic rings were prepared from young (7-9 weeks old) and senescent (65-70 weeks old) WKY and SHR rats. Changes in isometric tension elicited by 5-HT, in the absence or in the presence of N(G)-nitro-L-arginine methyl ester (L-NAME) or indomethacin were recorded. RESULTS: In aorta from WKY and SHR, 5-HT elicited concentration-dependent contractions, which were increased by endothelium removal. The ability of endothelium to depress contractile response to 5-HT was found to be reduced in vessels from senescent animals, mainly in SHR. L-NAME increased the sensitivity and maximal effect to 5-HT in endothelium-intact but not in denuded aortic rings from young WKY rats. The effect of L-NAME was lower in young SHR compared with age-matched WKY rats, but it did not modify the response to 5-HT in senescent rats. Indomethacin did not affect contraction in arteries from young WKY or in denuded aortic rings from young SHR and aged WKY. In contrast, the inhibitor attenuated the response in endothelium-intact vessels from young SHR and aged WKY, and this effect was more marked in arteries with and without endothelium from senescent SHR. Thus, inhibition of cyclooxygenases by indomethacin revealed an enhanced endothelium-dependent modulation of contraction in senescent and hypertensive rats. CONCLUSIONS: Results indicate that hypertension and aging decrease the negative modulator role of endothelium, in 5-HT-induced vasoconstriction in aorta from WKY and SHR. Data also point out that endothelial dysfunction involves an increased formation of vasoconstrictor prostanoids, which counteract nitric oxide effects. In addition, SHR endothelium releases contractile prostanoids at an early stage of hypertension, whereas in old SHR vascular smooth muscle also releases prostanoids, which contribute to 5-HT-induced contraction.     

用放免测定观察自发性高血压大鼠脑底动脉上血管活性肠肽和P物质含量的变化

应用放射免疫分析的方法，观察了自发性高血压大鼠（ＳＨＲ）脑底动脉上血管活性肠肽（ＶＩＰ）和Ｐ物质（ＳＰ）含量的变化．结果表明，ＳＨＲ各主要脑底动脉ＳＰ的含量在２．６０～３．５１ｐｇ／ｍｇ之间．大脑前动脉（ＡＣＡ）ＳＰ的含量ＳＨＲ比对照京都Ｗｉｓｔａｒ（ＷＫＹ）大鼠小，在其它脑底动脉上ＳＰ的含量ＳＨＲ和ＷＫＹ大鼠无差异．ＳＨＲ各主要脑底动脉上的ＶＩＰ含量在２．３０～２．５５ｐｇ／ｍｇ之间，和ＷＫＹ大鼠均无明显差异．同时对ＳＨＲ脑底动脉上肽类物质含量的变化的意义作了进一步的讨论．     

Mechanisms involved in the hypotensive effect of a kappa-opioid receptor agonist in hypertensive rats

BACKGROUND: It remains unclear whether the activation of kappa-opioid receptors has strong hypotensive effects under hypertensive condition, and the underlying mechanisms have not yet been investigated. Therefore, the present study is designed to use spontaneously hypertensive rats (SHR) to investigate the effects of a kappa-opioid receptor agonist on the regulation of urinary formation in hypertensive conditions and to identify its underlying mechanism. METHODS: The hemodynamics, urine flow rate, vasodilatation of isolated renal artery, and plasma hormones were determined by physiological in vivo experimental technique, isolated artery perfusion technique and radioimmunoassay. RESULTS: Intravenous administration of U50, 448H significantly decreased mean arterial blood pressure in both Wistar-Kyoto (WKY) rats and SHR. However, the blood pressure vasodepressor effect of U50, 448H was much more profound in SHR than in WKY rats. Administration of U50, 448H in SHR not only caused significantly greater effects in increasing urine volume and decreasing plasma anti-diuretic hormone than in WKY rats, but also caused significant reduction in plasma angiotensin. Moreover, vasodilatory effect of U50, 488H was significantly exhibited in the renal artery segments isolated from SHR. All effects described above were abolished by nor-binaltorphimine. CONCLUSIONS: These data indicate that the depressor effect of U50, 488H in SHR is significantly stronger than that in WKY rats, and the effect is mediated or modulated by a kappa-opioid receptor sensitive mechanism. The sensitized hypotensive effect of U50, 488H in SHR may be attributed, in part, to its vasodilatory effect, enhanced beneficial effect on plasma humoral factors, and stronger diuretic effect in these hypertensive animals.     

细胞外调节激酶的表达及活化在不同年龄自发性高血压大鼠心肌肥厚中的作用

目的:研究不同年龄的自发性高血压大鼠(spontaneously hypertensive rat,SHR)心室肌组织中细胞外调节激酶(extracellular signal-regulated kinases,ERKs)的表达及活化与心肌肥厚的关系.方法:选择Wistar Kyoto(WKY)大鼠作对照,SHR和WKY大鼠按年龄分为5周、8周、14周和24周各4组,以左心室质量与体重的比值反映心肌肥厚的程度;采用Western blot方法测定大鼠左心室心肌组织中基础表达ERK (basal ERK,b-ERK)和磷酸化ERK(phosphorylated-ERK,p-ERK)的水平.结果:①与相同周龄WKY大鼠比较,SHR自8周龄起血压明显升高(P<0.001),14周后心肌肥厚指数明显增加(P<0.01).②各年龄组SHR与相同周龄WKY大鼠b-ERK水平比较均无明显差异(P>0.05). ③5周龄SHR p-ERK水平与同龄WKY大鼠无差异,8到24周SHR大鼠p-ERK水平明显高于同龄WKY大鼠(P<0.01).④心肌肥厚指数与b-ERK量无明显相关性,与p-ERK量呈正相关. 结论:在SHR大鼠心肌肥厚形成中,心肌组织b-ERK没有增加,p-ERK水平增高,ERK活性增加参与高血压心肌肥厚过程.     

自发性高血压大鼠心肾交感神经的分布状况

目的探讨自发性高血压大鼠心脏及肾脏交感神经的分布状况。方法选取6及12周龄的自发性高血压大鼠（SHR）和相应周龄的同源正常血压大鼠（WKY），以儿茶酚胺合成限速酶酪氨酸羟化酶（TH）的表达作为交感神经分布的标志，采用免疫组织化学检测TH，尾套法检测大鼠血压及心率。结果6及12周龄的SHR血压及心率高于相应周龄的WKY 鼠。6 及12 周龄的SHR心脏及肾脏TH 的表达高于相应周龄的WKY 鼠。SHR12 周龄时肾脏TH的表达高于6 周龄，心脏TH的表达在2 个周龄组差异无统计学意义。结论SHR心及肾脏交感神经纤维分布密度增加，并且随着高血压的进展，肾脏交感神经纤维分布密度有增加的趋势。