自发性高血压大鼠肾上腺髓质素含量与中性内肽酶分布的关系

目的测定自发性高血压大鼠(SHR) 与WKY大鼠组织肾上腺髓质素(ADM)含量和中性内肽酶(NEP)活性及其表达水平,以探讨NEP的变化在高血压时组织ADM水平升高中的意义.方法采用放射免疫分析方法和荧光分光光度法分别检测血浆和组织的ADM含量和NEP的活性,同时用半定量RT-PCR和免疫组织化学染色法分别检测组织NEP mRNA和NEP蛋白的表达和分布.结果 ADM和NEP广泛分布于大鼠的血浆和组织,SHR的ADM含量在各组织普遍高于WKY大鼠.SHR心脏和小肠NEP的活性和mRNA表达均显著低于WKY大鼠,ADM含量与NEP活性呈负相关.反之,SHR血浆和肾脏NEP活性、肾脏NEP mRNA水平与蛋白量均高于WKY大鼠,ADM含量与NEP活性呈正相关.在肺脏和主动脉,NEP的活性无明显变化.结论 NEP在自发性高血压大鼠各组织器官中的变化与ADM含量的变化不一致,提示高血压时组织局部的NEP对ADM含量的影响不同.     

人参皂苷Rg2对SHR大鼠血压及肾脏MMP2、MMP9表达的影响

目的 研究人参皂苷Rg2对自发性高血压大鼠(SHR)血压的影响及肾脏组织中基质金属蛋白酶（MMP）2和MMP9表达的影响。方法 采用无创大鼠鼠尾测压仪测量各组大鼠动脉血压及心率，Realtime PCR检测大鼠肾脏组织MMP2、MMP9的mRNA水平，Western Blot检测MMP2、MMP9的蛋白水平。结果 与WKY大鼠相比，SHR大鼠的体质量、肾脏质量、心率均无明显变化，血压包括收缩压、舒张压及平均动脉压均显著性增高(P<0.05)。Rg2处理4周后，SHR大鼠的血压均显著性降低(P<0.05)，WKY大鼠的血压无明显变化。SHR大鼠的MMP2和MMP9的mRNA水平均明显高于WKY大鼠(P<0.05)。Rg2处理4周后，SHR大鼠的MMP2和MMP9的mRNA水平均显著下降(P<0.05)，WKY大鼠的MMP2和MMP9的mRNA水平无明显变化。Rg2处理后SHR大鼠的MMP2和MMP9蛋白变化趋势与mRNA变化趋势一致。结论 Rg2显著降低SHR大鼠的血压以及肾脏组织MMP2和MMP9的表达。     

自发性高血压大鼠心血管组织中肾上腺髓质素2受体系统的变化

目的:探讨自发性高血压大鼠(SHR)心血管组织中肾上腺髓质素2(ADM2)及其受体系统的基因表达和蛋白水平变化,以及与ADM2血浆水平的相互关系.方法:8只11周龄的雄性SHR(SHR组),8只同龄的雄性Wistar Kyoto大鼠(WKY组).半定量RT-PCR方法测定大鼠心血管组织中ADM2及其受体系统降钙素受体样受体(CRLR)和受体活性修饰蛋白(RAMPs)mRNA水平;Western blot法测定心血管组织中CRLR和RAMPs的蛋白含量;放射免疫法测定血浆中ADM2含量.结果:①SHR心肌中ADM2、CRLR、RAMP1、RAMP2和RAMP3的mRNA水平较WKY组分别高76.1%、41.6%、69.2%、48.3%和109.1%(均P＜0.05);主动脉中分别高171.11%(P＜0.01)、69.9%(P＜0.05)、100.09%(P＜0.01)、131.8 0%和69.7%(均P＜0.05).②SHR心肌中CRLR、RAMP1和RAMP3的蛋白水平较WKY组分别高136.0%、60.3%、63.9%(均P＜0.05),而RAMP2则显著增高292.5%(P＜0.01);SHR主动脉中CRLR、RAMP1、RAMP2和RAMP3的蛋白水平较WKY组分别高112.4%、92.3%、41.1%和67.7%(均P＜0.01).③SHR的ADM2血浆含量和受体的蛋白水平-CRLR、RAMP1、RAMP2在主动脉中的含量呈显著正相关(r=0.883 8,0.929 9,0.888 1,均P＜0.05).结论:ADM2及其受体系统在原发性高血压的发生发展过程中可能具有重要的病理生理意义.     

水孔蛋白2（AQP2）在SHR和WKY大鼠肾脏的不同表达

目的　本研究旨在探讨SHR和WKY大鼠肾脏中 ,AQP2mRNA是否存在差异表达及其和精氨酸加压素 (AVP)的关系。方法　成年SHR和WKY大鼠各 9只 ,12周龄 ,体重 2 0 0～ 3 0 0g。断头取血 ,放免法测定血浆AVP含量。取肾脏近髓组织 10 0mg ,RT PCR法检测大鼠肾脏AQP2mRNA的表达量 ,数据以 x±s表示。结果　SHR肾脏AQP2mRNA表达水平显著高于WKY( 0 80 1± 0 0 8vs 0 5 71± 0 0 6,P <0 0 5 ) ,SHR血浆中AVP的浓度显著高于WKY( 90± 17 83vs60 82± 12 5 9) pg/mL。结论　SHR肾脏AQP2mRNA表达量上调 ,可能在SHR高血压的发生发展中发挥着一定的作用 ,AVP可能介导了AQP2mRNA表达     

水孔蛋白2(AQP2)在SHR和WKY大鼠肾脏的不同表达

目的本研究旨在探讨SHR和WKY大鼠肾脏中,AQP2 mRNA是否存在差异表达及其和精氨酸加压素(AVP)的关系.方法成年SHR和WKY大鼠各9只,12周龄,体重200～300 g.断头取血,放免法测定血浆AVP含量.取肾脏近髓组织100 mg,RT-PCR法检测大鼠肾脏AQP2mRNA的表达量,数据以-x±s表示.结果 SHR肾脏AQP2mRNA表达水平显著高于WKY(0.801±0.08vs0.571±0.06,P＜0.05),SHR血浆中AVP的浓度显著高于WKY(90±17.83 vs60.82±12.59)pg/mL.结论 SHR肾脏AQP2 mRNA表达量上调,可能在SHR高血压的发生发展中发挥着一定的作用,AVP可能介导了AQP2 mRNA表达.     

自发性高血压大鼠肾脏血管紧张素转换酶2 mRNA转录及其蛋白表达

目的观察不同月龄自发性高血压大鼠(SHR)肾脏血管紧张素转换酶2(ACE2) mRNA转录及其蛋白表达,初步探讨ACE2在高血压发生、发展过程中的可能作用。方法雄性SHR1月龄组(S1)、2月龄组(S2)、3月龄组(S3)、6月龄组(S6)和9月龄组(S9)共5组,每组各6只,各组均有相应月龄匹配的Wistar-Kyoto(WKY)大鼠作对照。采用RBP-Ⅰ型大鼠血压心率测定仪测量大鼠尾动脉收缩压(SBP);逆转录聚合酶链式反应(RT-PCR)法检测肾脏ACE2 mRNA的转录水平;免疫组化染色结合计算机图像分析方法测定肾脏ACE2蛋白的表达水平。结果1)SHR的SBP随着月龄的增加而上升,6月龄后趋于稳定。2)SHR和WKY肾脏ACE2蛋白和 mRNA水平均随着月份的增加而增加,3月龄时达高峰,6月龄后趋于稳定;且SHR肾脏ACE2蛋白和 mRNA水平均低于同龄的WKY。S1肾脏髓质内侧部ACE2免疫染色阳性面积百分比较皮质和髓质外侧部高,与1月后的分布相反。结论1)SHR肾脏ACE2 mRNA和蛋白的表达水平比WKY大鼠低。2)大鼠肾脏ACE2 mRNA和蛋白的表达具有时间和部位分布上的差异。     

缬沙坦对老龄高血压大鼠肾脏重构及MMP-9、c-fos表达的影响

目的 评价应用缬沙坦阻断RAAS系统对老龄自发性高血压(SHR)大鼠(SHR)肾脏MMP-9、c-fos的影响.方法 20只40周龄老龄SHR随机分组:SHR对照组、缬沙坦组,另设老龄WKY对照组.12 w后取肾脏标本,免疫组化法检测肾脏Ⅳ型胶原的表达;RT-PCR检测MMP-9、c-fos mRNA的表达,Western印迹检测MMP-9、c-fos蛋白的表达水平.结果 免疫组化显示:与WKY对照组比较,SHR对照组Ⅳ型胶原水平明显增高,缬沙坦组能明显降低SHR肾脏Ⅳ型胶原表达水平;实时定量RT-PCR和Western印迹显示,与WKY对照组比较,SHR对照组MMP-9、c-fos mRNA和蛋白表达明显增高,药物组显著降低其表达水平.结论 应用缬沙坦阻断RAAS系统能够有效地改善和逆转老龄SHR大鼠的肾脏重构.     

自发性高血压大鼠肾脏血管紧张素转换酶2 mRNA转录及其蛋白表达

目的 观察不同月龄自发性高血压大鼠(SHR)肾脏血管紧张素转换酶2(ACE2)mRNA转录及其蛋白表达,初步探讨ACE2在高血压发生、发展过程中的可能作用.方法 雄性SHR 1月龄组(S1)、2月龄组(S2)、3月龄组(S3)、6月龄组(S6)和9月龄组(S9)共5组,每组各6只,各组均有相应月龄匹配的Wistar-Kyoto(WKY)大鼠作对照.采用RBP-Ⅰ型大鼠血压心率测定仪测量大鼠尾动脉收缩压(SBP);逆转录聚合酶链式反应(RT-PCR)法检测肾脏ACE2 mRNA的转录水平;免疫组化染色结合计算机图像分析方法 测定肾脏ACE2蛋白的表达水平.结果 1)SHR的SBP随着月龄的增加而上升,6月龄后趋于稳定.2)SHR和WKY肾脏ACE2蛋白和mRNA水平均随着月份的增加而增加,3月龄时达高峰,6月龄后趋于稳定;且SHR肾脏ACE2蛋白和mRNA水平均低于同龄的WKY.S1肾脏髓质内侧部ACE2免疫染色阳性面积百分比较皮质和髓质外侧部高,与1月后的分布相反.结论 1)SHR肾脏ACE2 mRNA和蛋白的表达水平比WKY大鼠低.2)大鼠肾脏ACE2 mRNA和蛋白的表达具有时间和部位分布上的差异.     

高血压大鼠冠状动脉平滑肌细胞大电导钙激活钾通道的变化

目的研究在高血压背景下大电导钙激活钾(BK)通道的功能改变及其机制。方法用酶解消化方法分离12～16周龄自发性高血压大鼠(SHR)和WKY大鼠冠状动脉平滑肌细胞(CASMCS),采用膜片钳全细胞模式记录SHR和WKY大鼠CASMCSBK电流,SHR和WKY大鼠BKα亚基和β1亚基mRNA水平用实时定量取聚合酶链式反应和凝胶电泳测定,蛋白水平表达用免疫组化的方法测定。结果 SHR大鼠CASMCS(n=6)BK电流密度比WKY(n=7)高2.03±0.62(P0.01);在mRNA水平,BKβ1亚基表达SHR组明显高于WKY组5.534±1.03倍(n=4,P0.05),BKα亚基表达则无明显差异(1.266±0.12,n=4,P0.05);BKβ1亚基和α亚基的表达SHR大鼠高于WKY大鼠。结论 SHR大鼠CASMCSBK电流密度比WKY大鼠增大,在mRNA和蛋白水平上BKβ1亚基表达也比WKY大鼠增强,这种变化可能是机体在高血压时自我调节的结果 。     

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,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ET-1含量及mRNA均高于WKY组,TXL组ET-1含量及mRNA表达低于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。     

Relationship between the contents of adrenomedullin and distributions of neutral endopeptidase in blood and tissues of spontaneously hypertensive rats.

Adrenomedullin (ADM) is a multifunctional peptide with important roles in the cardiovascular system, especially in the adjustment of cardiovascular and renal homeostasis. ADM is present in plasma, organs and tissues, and its activity increases during hypertension. It remains unknown whether the clearance of this peptide is altered during hypertension. Neutral endopeptidase (NEP) is the major enzyme in ADM's degradation. We observed the activity and distribution of NEP and the expression of its mRNA in the plasma, cardiac ventricle, aorta, jejunum and kidney of spontaneously hypertensive rats (SHRs) in order to study the possible role of NEP in elevating tissue ADM concentrations during hypertension. ADM and NEP were diffuse in all tissues studied. The level of tissue ADM was generally higher in SHR tissues than in control tissues, except in the renal medulla, and its mRNA expression was higher in all tissues. Plasma NEP activity, general NEP activity and the expression of NEP mRNA in the left ventricle, aorta and jejunum in SHRs was lower than that of controls, and the level of ADM was inversely correlated with NEP activity. NEP activity and mRNA and protein expression in SHR kidneys were higher than in control kidneys; moreover, the ADM content was positively correlated with NEP activity in the renal cortex. NEP activity in the lung of SHRs did not differ from that of controls. Thus, in SHRs, the local concentration and action of ADM in the tissues may be differentially regulated by NEP.     

自发性高血压大鼠心肌fas基因表达与左室肥厚关系探讨

目的 探讨自发性高血压大鼠（SHR）心肌fas表达及其与左室肥厚的关系。方法 自发性高血压大鼠（SHR）与正常血压大鼠各16号，尾套法测收缩压，逆转录-聚合酶边反应（RT-PCR）法测心肌fas mRNA表达。结果 与WKY相比，SHR心肌fas表达、左室重量指数(LVMI)均显著升高，且二者呈正相关。结论 自发性高血压大鼠早期心肌肥厚时心肌fas表达已经升高，可能参与后期心衰的发生。     

自发性高血压大鼠心脏重构与ACE2 mRNA的表达

目的:观察不同月龄的自发性高血压大鼠(SHR)的心脏血管紧张素转换酶2(ACE2)mRNA表达水平,探讨心脏重构与ACE2的内在联系。方法:将12周龄雄性SHR 18只和12周龄WKY Wistar-Kyoto rats大鼠18只随机分为两组,从WKY大鼠组和SHR组中各抽取9只处死,剩余的9只再喂养12周后处死。测量大鼠心脏的质量(HW)与体质量(BW)并计算HW/BW的比值。以实时定量RT-PCR法检测ACE2 mRNA的表达。结果:①与同周龄WKY大鼠组比较,SHR组HW/BW的比值显著增加(P0.01);与12周龄SHR组比较,24周龄SHR组的HW/BW显著增加(P0.05)。②与同周龄的WKY大鼠组比较,SHR组ACE2 mRNA的表达显著降低(P0.01);与12周龄的SHR组比较,24周龄的SHR组ACE2 mRNA的表达显著降低(P0.01)。结论:自发性高血压大鼠心脏重构伴随着心脏中ACE2 mRNA的表达下调。     

Improvement of Vascular Remodeling in Spontaneous Hypertensive Rats with Traditional Chinese Medicine

Qin-Dan-Jiang-Ya-Tang (QDJYT) is a traditional Chinese herbal medicine for the treatment of hypertension. The effect of QDJYT on blood pressure (BP) and vascular remodeling in hypertension was investigated in the model of spontaneous hypertensive rats (SHR). Sixteen SHRs were divided into two groups: the SHR group and the SHR+ QDJYT group. Eight Wistar-Kyoto (WKY) rats were in the normal control group. QDJYT (750mg/kg) was orally administered daily for 12 weeks to the SHR+QDJYT group. After 12 weeks, thoracic aortas were segregated. The media thickness (MT) and the lumen diameter (LD) of the aortic wall, the ratios of MT to LD, the expression of basic fibroblast growth factor (bFGF) mRNA, and the level of its proteinic production were examined by histology, real-time PCR, and Western blot analysis, respectively. It was observed in our study that MT, MT/LD, the expression of bFGF mRNA, and the level of its proteinic production in aortic walls were higher in SHRs than in WKY rats. However, in the SHRs treated with QDJYT, we found MT, MT/LD, the expression of bFGF mRNA and the level of its proteinic production were lower than SHRs. These results suggest that QDJYT can improve the vascular remodeling in SHRs, and the mechanisms may be related to the suppressive effect of QDJYT on bFGF mRNA and its proteic productions in the aortic walls of SHRs.     

Improvement of vascular remodeling in spontaneous hypertensive rats with traditional Chinese medicine

Qin-Dan-Jiang-Ya-Tang (QDJYT) is a traditional Chinese herbal medicine for the treatment of hypertension. The effect of QDJYT on blood pressure (BP) and vascular remodeling in hypertension was investigated in the model of spontaneous hypertensive rats (SHR). Sixteen SHRs were divided into two groups: the SHR group and the SHR+ QDJYT group. Eight Wistar-Kyoto (WKY) rats were in the normal control group. QDJYT (750 mg/kg) was orally administered daily for 12 weeks to the SHR+QDJYT group. After 12 weeks, thoracic aortas were segregated. The media thickness (MT) and the lumen diameter (LD) of the aortic wall, the ratios of MT to LD, the expression of basic fibroblast growth factor (bFGF) mRNA, and the level of its proteinic production were examined by histology, real-time PCR, and Western blot analysis, respectively. It was observed in our study that MT, MT/LD, the expression of bFGF mRNA, and the level of its proteinic production in aortic walls were higher in SHRs than in WKY rats. However, in the SHRs treated with QDJYT, we found MT, MT/LD, the expression of bFGF mRNA and the level of its proteinic production were lower than SHRs. These results suggest that QDJYT can improve the vascular remodeling in SHRs, and the mechanisms may be related to the suppressive effect of QDJYT on bFGF mRNA and its proteic productions in the aortic walls of SHRs.     

Differential regulation of cardiac adrenomedullin and natriuretic peptide gene expression by AT1 receptor antagonism and ACE inhibition in normotensive and hypertensive rats

OBJECTIVE: To study the effects of long-term treatment with the type 1 angiotensin (AT1) receptor antagonist losartan and the angiotensin-converting enzyme (ACE) inhibitor enalapril, on cardiac adrenomedullin (ADM), atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) gene expression. METHODS: Spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats were given losartan (15 mg/kg per day) or enalapril (4 mg/kg per day) orally for 10 weeks. The effects of drugs on systolic blood pressure, cardiac hypertrophy, ANP, BNP and ADM mRNA and immunoreactive-ANP (IR)-ANP, IR-BNP and IR-ADM levels in the left ventricle and atria were compared. RESULTS: Losartan and enalapril treatments completely inhibited the increase of systolic blood pressure occurring with ageing in SHR. The ratio of heart to body weight was reduced in both losartan- and enalapril-treated SHR and WKY rats. Treatment with losartan or enalapril reduced left ventricular ANP mRNA and IR-ANP in both strains, and ventricular BNP mRNA levels in SHR rats. Inhibition of ACE, AT1 receptor antagonism, changes in blood pressure or cardiac mass had no effect on left ventricular ADM gene expression in SHR and WKY rats. In addition, atrial IR-ANP and IR-ADM levels increased in SHR whereas IR-BNP levels decreased in WKY and SHR rats in response to drug treatments. CONCLUSIONS: Our results show that ventricular ADM synthesis is an insensitive marker of changes in haemodynamic load or cardiac hypertrophy. Furthermore, the expression of ADM, ANP and BNP genes is differently regulated both in the left ventricle and atria in response to AT1 receptor antagonism and ACE inhibition.     

自发性高血压大鼠血管壁肌球蛋白轻链磷酸酶含量的研究

目的：肌球蛋白轻链磷酸酶（MLCP）水平与血管的收缩与舒张功能有着重要的关系。本研究探讨MLCP与自发性高血压大鼠（SHR）高血压发病机制之间的关系。方法：在摄氏4度的环境下，取SHR与正常血压WKY大鼠各10只断头处死，迅速取其大动脉，称重速冻后将血管磨成匀浆，置于缓冲液中，并通过离心提取蛋白质，校正两组总蛋白的浓度后，分别应用（SDS-PAGE）、Western印迹杂交和化学发光方法测定SHR与WKY大鼠动脉血管壁MLCP的130kD、38kD、21kD三个亚单位的含量，对显影结果进一步进行吸光度扫描分析。并进行两组间的比较。结果：SHR的MLCP130kD亚单位的含量明显高于WKY大鼠（P〈0．01），而38kD和21kD亚单位含量则明显低于WKY大鼠（P〈0．01）。结论：SHR和WKY大鼠血管壁MLCP的130kD、38kD、21kD三个亚单位含量有着明显的差异，提示MLCP结构或功能的异常可能与SHR高血压的发病有关。     

The Mechanism of Distinct Diurnal Variations of Renin-Angiotensin System in Aorta and Heart of Spontaneously Hypertensive Rats

Diurnal variations in plasminogen activator inhibitor-1 mRNA expression are different between the spontaneously hypertensive rats (SHRs) and the Wistar-Kyoto (WKY) rats, and between the aorta and the heart. To elucidate the mechanisms, we examined diurnal changes in the circulating renin-angiotensin system in the SHR and WKY rats. Diurnal variations in plasma renin activity (PRA), plasma angiotensin I, and aldosterone concentrations were similar between the SHR and WKY rats. On the other hand, plasma angiotensin II (Ang II) concentration in the SHR was lower than that in the WKY rats at most time points, but increased to the level of the WKY rats in the late light phase. Treatment with AT1 receptor antagonist candesartan increased plasma Ang II concentration except at ZT 8 and lessened its diurnal variation in the SHR. At the peak in plasma Ang II in the SHR, Ang II regulated genes such as transforming growth factor-β1 and p22phox were upregulated in the aorta. On the other hand, these genes were upregulated throughout the day in the heart of SHR. Candesartan treatment increased AT1a receptor mRNA expression in the heart but not in the aorta of SHR. These findings suggest that an AT1 receptor-mediated mechanism might cause a surge in plasma Ang II concentration at the late light phase in the SHR. Homologous down-regulation of AT1a receptor by Ang II may dampen the effect of a surge in plasma Ang II concentration in the heart of SHR.     

ERK表达及活化在自发性高血压大鼠心肌肥厚中作用的研究

目的　以SHR大鼠作为自发性高血压动物模型 ,研究ERK表达及活化在高血压并发左心室肥厚 (LVH)中的作用。方法　SHR大鼠按年龄分为 8周、16周和 2 4周三组 ,以Wistar大鼠作为对照。ERK表达及活性定量测定采用WesternBlot方法。结果　SHR左室质量指数与磷酸化ERK水平正相关。 2 4周龄SHR大鼠基础ERK表达水平较 8周龄和 16周龄减少 ,亦明显低于同龄Wistar大鼠 (P =0 0 0 3) ;SHR大鼠ERK活化程度高于同龄Wistar大鼠 ,随年龄增加 ,SHR磷酸化ERK表达量增加。结论　ERK的活化参与高血压心肌肥厚的发病。