不同年龄自发性高血压大鼠心脏AT2R的表达与心肌纤维化

目的观察不同年龄自发性高血压大鼠（SHR）心脏AT2R的表达水平及心肌胶原含量,探讨AT2R在高血压发生、发展过程中的作用。方法 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）雄性SHR共五组,每组各6只,各组均有相应月龄的Wistar-Kyoto大鼠（WKY）作对照。采用RBP-I型大鼠血压心率测定仪测量大鼠动脉收缩压（SBP）;放免法（RIA）测定血浆血管紧张素Ⅱ（AngⅡ）;免疫组化染色结合计算机图像分析方法测定心脏AT2R的表达水平,天狼星红胶原染色大鼠的心脏切片。结果 1.SHR SBP随着月龄的增加呈持续上升（P〈0.05）,SHR的SBP均高于相应配对的WKY组（P〈0.05）。2.一个月后SHR血浆AngⅡ浓度均高于S1（P〈0.05）,一个月后SHR血浆AngⅡ浓度均高于相应配对的WKY组（P〈0.05）。3.SHR心脏AT2R免疫染色阳性面积比随着月份的增加而降低,SHR心脏AT2R免疫染色阳性面积比均低于相应配对的WKY组（P﹤0.05）4.SHR心肌中的胶原含量随着月龄的增加而增加。结论 SHR心脏AT2R表达水平比WKY低,并随着年龄的增加而降低。SHR心肌中的胶原含量随着月龄的增加而增加,而WKY无类似趋势。     

TGF-β1在自发性高血压大鼠肾损害中作用的研究

目的研究转化生长因子-β1(transforming growth factor-β1,TGF-β1)在自发性高血压大鼠(spontaneously hypertertensive rat,SHR)肾脏的表达及其与肾损害的关系.方法以同龄雄性正常血压(Wistar Kyoto,WKY)和自发性高血压大鼠为研究对象,分别于12周龄和24周龄时检测两种大鼠尾动脉血压、肾功能及β2微球蛋白(β2-MG),并采用免疫组织化学的方法检测TGF-β1在肾脏中的表达.结果同WKY组比较, SHR组24周时β2-MG显著增高(P<0.01);而且尾动脉血压显著性增高;而尿素氮和血肌酐的差异无显著性(P>0.01).TGF-β1在WKY组肾小管的表达无或极微量;在SHR组的肾小球有少量表达,但在肾小管的表达显著,且随高血压病程的进展, TGF-β1的表达显著性增加(P<0.01).结论 TGF-β1在自发性高血压大鼠肾小管的表达显著增加,与肾损害的各项指标呈正相关.     

自发性高血压大鼠心肌肥厚和心肌MAPK、AngⅡ的关系

放免法测定自发性高血压大鼠（ＳＨＲ）血浆及心肌血管紧张素Ⅱ（ＡｎｇⅡ）含量,凝胶内磷酸化法测定心肌丝裂素活化蛋白激酶活性（ＭＡＰＫ）,以心脏重／体重表示心肌肥厚程度。结果表明：与４个月的ＷＫＹ大鼠比较,４个月的ＳＨＲ血浆和心肌组织ＡｎｇⅡ及心肌ＭＡＰＫ活性分别增加了２１８．６％、１０１．２％和１０７．０％,心肌肥大程度严重,其中ＭＡＰＫ活性与心肌肥大程度呈明显正相关。提示４个月ＳＨＲ心肌肥厚可能是     

肾性和自发性高血压大鼠心肌肥大前后心肌Gαq/11含量的变化

目的 :探讨Gαq/11在不同原因所致心肌肥大中的变化。方法 :两肾一夹肾性高血压大鼠 (RHR)和自发性高血压大鼠(SHR)模型 ,测定动脉血压和心肌肥大指数 ,放免法测定心肌血管紧张素II(AngII)含量 ,免疫印迹法测定心肌Gαq/11含量。 结果 :RHR术后 1周动脉血压、心肌肥大指数及Gαq/11含量与假手术组无差异 ,心肌AngII含量显著升高 (P <0 .0 1) ;术后 8周上述各指标均较假手术组升高。 12周龄SHR动脉血压、心肌肥大指数和AngⅡ含量均较同龄WKY升高 (P均 <0 .0 1) ,但心肌Gαq/11含量却无明显变化 ;4周龄时上述各指标与同龄对照相比均无明显差异。 结论 :Gαq/11在肾性和自发性高血压心肌肥大中有不同变化。     

不同年龄白发性高血压大鼠肾脏AT1R和AT2R的表达

目的本研究观察不同月龄自发性高血压大鼠（SHR）肾脏ALR和ALR表达,初步探讨AT1R和AT2R在高血压发生、发展过程中的可能作用。方法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（墨）雄性SHR共5组,每组各6只,各组均有相应月龄匹配的Wistar-Kyoto大鼠（WKY）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）;放免法测定血浆血管紧张素Ⅱ（AngⅡ）;免疫组化染色结合计算机图像分析方法测定肾脏AT1R和ALR表达水平。结果（1）SHR SBP随着月龄的增加而上升,S6后趋于稳定。（2）1个月后SHR血浆AngⅡ浓度均高于S1（P〈0.05）,而S2、S3、S6和S9之间无明显差别（P〉0.05）;1个月后SHR血浆AngⅡ浓度均高于相应配对的WKY组（P〈0.05）;而WKY各月龄组均无明显差别（P〉0.05）。（3）SHR肾脏AT1R随着月份的增加而增加（P〈0.05）,且高于相应配对的WKY组（P〈0.05）。SHR肾脏ABR随着月份的增加而降低,S6明显降低（P〈0.05）,S6和S9比较无明显差别（P〉0.05）;且均低于相应配对的WKY组（P〈0.05）。WKY各月龄组AT1R和AT2R无明显差别（P〉0.05）。结论SHR肾脏AT1R表达水平比WKY高,并随着年龄的增加而递增;AT2R表达水平比WKY低,并随着年龄的增加而降低。     

感觉神经损伤性盐敏感性高血压大鼠心、肾AT1R的表达

目的对感觉神经损伤性盐敏感性高血压大鼠的心肌、肾脏组织中的血管紧张素Ⅱ1型受体（AT1R）在mRNA和受体水平的表达进行检测,探讨AT1R与盐敏感性高血压的关系。方法用乳鼠皮下注射辣椒辣素法建立模型。哺乳期后,大鼠被随机分成4组：对照＋正常盐饮食组（CON-NS）;对照＋高盐饮食组（CON-HS）;辣椒辣素＋正常盐饮食组（CAP-NS）;辣椒辣素＋高盐饮食组（CAP-HS）。至7周龄（分组饲养后第4周）处死大鼠,免疫组织化学方法和反转录-聚合酶链式反应（RT-PCR）分别检测大鼠心肌和肾脏AT1R蛋白,以及AT1 R mRNA的表达。结果①Wistar大鼠在给予不同程度的感觉神经损伤和饲料干预后,各组大鼠尾部收缩压均有明显增加,最终CAP-HS组的尾收缩压显著高于其他三组（P〈0.01）。②免疫组织化学结果显示,CAP-HS组组织有显著的AT1R蛋白表达（P〈0.01）;CON-HS组肾脏、心肌组织中AT1R蛋白表达高于CON-NS组（P〈0.05）。③RT-PCR检测基因表达,与对照组CON-NS相比,实验组CAP-HS的AT1R mRNA表达显著升高（P〈0.01）;CON-HS组肾脏、心肌组织中AT1 R mRNA表达有显著性（P〈0.05）。结论感觉神经损伤性盐敏感性高血压大鼠心、肾AT1R表达升高,AT1R表达水平的差异可能与盐敏感性高血压的形成有关。     

氯沙坦对肾血管性高血压大鼠血清中血管紧张素Ⅱ-1受体自身抗体产生的影响

目的和方法：采用两肾一夹型肾血管性高血压（RVH）模型,以合成的大鼠血管紧张素Ⅱ－1受体（AT1R）细胞外第二环165－191位氨基酸序列作为特异性抗原,用ELISA法检测大鼠血清中血管紧张素Ⅱ－1受体自身抗体,动态观察（13周）氯沙坦（术后第2周开始,5mg/kg dig,连续12周）治疗对模型大鼠AT1R自身抗体产生的影响。结果：RVH组大鼠血清中AT1R自身抗体从术后1周起阳性率、滴度逐渐升高;给予氯沙坦治疗不仅可抑制模型大鼠心脏功能和结构的改变,而且使血清AT1R自身抗体的阳性率和滴度明显低于肾血管性高血压组。结论：氯沙坦有抑制AT1R自身抗体产生而达到降压的作用。     

肾血管性高血压大鼠发病过程中心血管AT1-受体自身抗体的变化

实验观察了肾血管性高血压（RVH）大鼠血浆中抗AT1－受体自身抗体在发病过程中的作用及其变化规律。采用两肾一夹Goldblatt RVH模型,以合成的大鼠AT1－受体细胞外第二环165－191位氨基酸序列作为特慢性抗原,用SA－ELISA法检测大鼠血清中抗AT1-受体自身抗体。结果表明,RVH模型组术后2周时大鼠血清中抗AT1－受体自身抗体的阳性率和平均滴度与术前相比明显增高,较高的阳性率和平均滴度持续几周后逐渐下降,12周时下降到正常水平。结果提示,自身免疫机制参与了高血压的形成,抗AT1－受体自身抗体可能与心肌肥厚有关。     

EMT促进自发性高血压大鼠主动脉纤维化

目的:探讨内皮间充质转化(endothelial-to-mesenchymal transition,EMT)是否促进自发性高血压大鼠主动脉纤维化及降压治疗对其干预作用。方法:将24只雄性自发性高血压大鼠(spontaneously hypertensive rats,SHR)随机分为SHR组(S组,蒸馏水灌胃)、哌唑嗪组(P组,哌唑嗪5 mg/(Kg×d)灌胃)和氯沙坦组(L组,氯沙坦10 mg/(Kg×d)灌胃),8只雄性WKY大鼠(W组,蒸馏水灌胃)作为对照组,各组分别干预8周后,通过Masson染色检测各组大鼠主动脉纤维化程度,免疫荧光染色及Western Blot检测各组大鼠主动脉I型胶原、CD31及FSP1蛋白表达变化。结果:Western blot及Masson染色显示从L组、P组到S组大鼠主动脉I型胶原含量依次增多,且主动脉壁厚度均显著大于W组(P0.05),但P组与L组大鼠主动脉管壁厚度无统计学差异(P=0.818);免疫荧光染色表明,各组高血压大鼠主动脉均存在FSP1及CD31共表达(FSP+CD31+)细胞,且从L组、P组到S组FSP+CD31+细胞依次增多;Western Blot检测表明,从W组、L组、P组到S组,CD31蛋白表达量逐渐降少,FSP1蛋白表达量依次增加,差异有统计学意义(P0.05)。结论:EMT可能参与了自发性高血压大鼠的主动脉纤维化,氯沙坦和哌唑嗪可能通过抑制EMT减轻主动脉纤维化。     

自发性高血压大鼠中枢血管紧张素Ⅱ的变化对中枢肾上腺素...

The content of norepinephrine (NE) and epinephrine (E) in the brain of spontaneously hypertensive rats has proved abnormal, but the cause remained unknown. It was shown in the recent work that NE content in pons, posterior hypothalamus, nucleus caudatus and E concentration in medulla oblongata, anterior and posterior hypothalamus of 12-week old stroke-prone spontaneously hypertensive rats (SHRSP) were much higher than those of age-matched Wister-Kyoto rats (WKY). SHRSP also showed higher levels of systolic blood pressure (SBP) and brain angiotensin II (A II) than WKY. Intracerebroventricular (icv) perfusion of angiotensin-converting enzyme inhibitor captopril (20 micrograms for each time and three times for each day for four weeks) inhibited the synthesis of brain A II and reduced SBP and NE, E contents in all examined brain areas in SHRSP and WKY. However, the effects of chronically perfused captopril on SBP and brain NE, E levels in SHRSP were much more significant than in WKY. The results indicate that the modulatory effects of central renin-angiotensin system (RAS) on central adrenergic and noradrenergic system might be overactivated in SHRSP, which might partially responsible for the abnormally high levels of NE, E in some of the brain areas of SHRSP.     

Exercise intensities modulate cognitive function in spontaneously hypertensive rats through oxidative mediated synaptic plasticity in hippocampus

Oxidative damage in the brain may lead to cognitive impairments. There was considerable debate regarding the beneficial effects of physical exercise on cognitive functions because exercise protocols have varied widely across studies. We investigated whether different exercise intensities alter performance on cognitive tasks. The experiment was performed on spontaneously hypertensive rats (6 months at the established phase of hypertension) distributed into 3 groups: sedentary, low-intensity exercise and high-intensity exercise. Systolic blood pressure measurements confirmed hypertension in spontaneously hypertensive rats. In comparison to normotensive Wistar-Kyoto rats, sedentary spontaneously hypertensive rats had similar escape latencies and a similar preference for the correct quadrant in the probe trial. Compared to the sedentary group, the low-intensity exercise group had significantly better improvements in spatial memory assessed by Morris water maze. Low-intensity exercise was associated with attenuated reactive oxygen species, as measured by dihydroethidine fluorescence and nitrotyrosine staining in the dentate gyrus of the hippocampus. This was coupled with increased numbers of neurons and dendritic spines as well as a significant upregulation of synaptic density. In contrast, the beneficial effects of low-intensity exercise are abolished in high-intensity exercise as shown by increased free radical levels and an impairment in spatial memory. We concluded that exercise is an effective strategy to improve spatial memory in spontaneously hypertensive rats even at an established phase of hypertension. Low-intensity exercise exhibited better improvement on cognitive deficits than high-intensity exercise by attenuating free radical levels and improving downstream synaptic plasticity.     

自发性高血压大鼠四氢生物碟呤治疗后动脉的结构及力学改变

目的：探讨长期四氢生物喋呤（BH4）治疗对自发性高血压大鼠（SHR）血管形态及血管力学性质的影响;方法：选用4周龄雄性SHR36只,随机分为实验组和对照组,每组18只。实验组每周2次腹腔注射BH420mg／kg,对照组注射等容量生理盐水,于实验第4、16和26周龄时各取6只测量动脉收缩压（SBP）,并使用计算机图像分析的方法分别测量主动脉血管零应力状态张开角、压力-直径关系及肠系膜动脉血管的壁／腔比值。结果：至BH4治疗后的第16和26周龄,SHR的SBP明显降低（P〈0．01）;实验组SHR胸主动脉张开角显著减小（P〈0．01）,压力-直径（P-D）关系曲线上移;实验组肠系膜动脉三级分支血管壁／腔（W／L）值减小（P〈0．05）。结论：BH4可以减弱由于长期高血压所导致的血管肥厚和管腔狭窄,恢复血管弹性。     

Factors regulating the renal circulation in spontaneously hypertensive rats

Hypertension is one of the leading causes of health morbidity and mortality which are linked to many life threatening diseases such as stroke heart problems and renal dysfunction.The integrity of renal microcirculation is crucial to maintaining the clearance and the excretory function in the normotensive and hypertensive conditions. Furthermore, any alteration in the renal function is involved in the pathophysiology of hypertension.The aim of this review is to provide a brief discussion of some factors that regulate renal haemodynamics in spontaneously hypertensive rats, an animal model of hypertension, and how these factors are linked to the disease.     

阿托伐他汀对自发性高血压大鼠p27蛋白表达及心肌细胞凋亡的影响

目的：观察阿托伐他汀对自发性高血压大鼠（SHR）p27蛋白表达及心肌细胞凋亡的影响。方法：将12只8周龄的雄性SHR随机分为2组（n=6）;蒸馏水饲养组（DW组）与阿托伐他汀治疗组（ATV组）,并以6只同周龄的正常血压大鼠（WKY）作为对照（WKY组）。分别采用RT-PCR与Western blot法检测p27的mRNA及蛋白表达水平;TUNEL法检测心肌细胞的凋亡;同时计算左室重与体重比,检测血脂水平。结果：阿托伐他汀治疗10周后,ATV组与DW组相比较,其①血脂水平及左室重、左室重与体重比均明显降低（P〈0.01）;②p27的mRNA及蛋白表达水平明显上调（P〈0.01）;③心肌细胞的凋亡率显著增高（P〈0.01）。结论：阿托伐他汀能够上调SHR的p27蛋白表达水平、促进其心肌细胞的凋亡,在某种程度上可能与其改善SHR心室肥厚的效应有关。     

Effects of chronic quercetin treatment on hepatic oxidative status of spontaneously hypertensive rats

The effects of chronic administration of an oral daily dose of quercetin (10 mg Kg^–1), the most abundant dietary flavonoid, were investigated on hepatic oxidative status in spontaneously hypertensive rats and normotensive Wistar Kyoto rats. Decreased liver glutathione peroxidase activity, increased liver total glutathione levels and increased both hepatic and plasmatic malondialdehyde concentrations were observed in spontaneously hypertensive rats when compared to Wistar Kyoto rats. In spontaneously hypertensive rats, treatment with quercetin for 5 weeks reduced blood pressure, increased glutathione peroxidase activity and reduced both plasma and hepatic malondialdehyde levels. However, none of these effects were observed in Wistar Kyoto rats. In conclusion, quercetin shows both antihypertensive and antioxidant properties in this model of genetic hypertension.     

Increased mRNA expression of cardiac renin-angiotensin system and collagen synthesis in spontaneously hypertensive rats

Hypertensive cardiac hypertrophy is associated with the accumulation of collagen in the myocardial interstitium. Previous studies have demonstrated that this myocardial fibrosis accounts for impaired myocardial stiffness and ventricular dysfunction. Although cardiac fibroblasts are responsible for the synthesis of fibrillar collagen, the factors that regulate collagen synthesis in cardiac fibroblasts are not fully understood. We investigated the effects of angiotensin II on cardiac collagen synthesis in cardiac fibroblasts. Cardiac fibroblasts of 10 week old spontaneously hypertensive rats and age-matched Wistar-Kyoto rats were prepared and maintained in culture medium supplemented with 10% fetal calf serum. The expression of mRNA of the renin-angiotensin system (renin, angiotensinogen, angiotensin converting enzyme) was determined by using a ribonuclease protection assay. Basal collagen synthesis in cardiac fibroblasts from spontaneously hypertensive rats was 1.6 fold greater than that in the cell of Wistar-Kyoto rats. Angiotensin II stimulated collagen synthesis in cardiac fibroblasts in a dose-dependent manner. The responsiveness of collagen production to angiotensin II was significantly enhanced in cardiac fibroblasts from spontaneously hypertensive rats (100 nM angiotensin II resulted in 185 ± 18% increase above basal levels, 185 ± 18 versus 128 ± 19% in Wistar-Kyoto rats p < 0.01). This effect was receptor-specific, because it was blocked by the competitive inhibitor saralasin and MK 954. These results indicate that collagen production was enhanced in cardiac fibroblasts from spontaneously hypertensive rats, that angiotensin II had a stimulatory effect on collagen synthesis in cardiac fibroblasts, and that cardiac fibroblasts from spontaneously hypertensive rats were hyper-responsive to stimulation by angiotensin II.Level of angiotensin and renin mRNA expressed in ventricles, and angiotensinogen mRNA expressed in fibroblasts from SHR were higher than those from WKY.These findings suggest that the cardiac renin-angiotensin system may play an important role in collagen accumulation in hypertensive cardiac hypertrophy.     

血小板源生长因子受体介导的信号转导在自发性高血压大鼠心肌肥大中的作用

为了探索血小板源生长因子 (platelet derivedgrowthfactor,PDGF)受体介导的信号转导在自发性高血压大鼠(spontaneouslyhypertensiverats,SHR)心肌肥大中的作用 ,实验采用Westernblot法检测SHR及其对照WKY大鼠心肌PDGF受体β和细胞外信号调节激酶 (extracellularsignal regulatedkinase1/ 2 ,ERK 1/ 2 )的蛋白表达和ERK 1/ 2磷酸化水平的变化。结果显示 :4周龄SHR的收缩压、舒张压、±dp/dtmax和心肌肥大指数与同龄WKY大鼠相比均无明显差异 ,而 12周龄SHR上述指标与同龄WKY大鼠相比均明显升高 ,表明 12周SHR已发生高血压 ,心脏收缩功能代偿性增强 ,并出现心肌肥大。 4周龄SHR心肌PDGF受体 β和ERK1/ 2的磷酸化水平以及ERK 1/ 2的蛋白表达水平与同龄对照相比均无明显变化 ,12周时SHR心肌PDGF受体 β的蛋白表达较同龄WKY增加 32 77% (P <　　　　　　　　　 0 0 5 ) ,PDGF受体介导的信号转导通路的下游信号分子ERK 1/ 2的磷酸化水平较同龄WKY升高 19 6 % (P =0 0 1) ,表明ERK 1/ 2的活化增加 ,但ERK 1/ 2的蛋白表达水平尚无变化。为进一步明确PDGF受体 β在心肌细胞生长中的作用及其与ERK 1/ 2活性的关系 ,采用PDGF BB刺激培养的乳鼠心肌细胞 ,发现 [3 H]亮氨酸掺入量明显增加 ,ERK 1/ 2的磷酸化水平明     

自发性高血压大鼠多组织炎症状态

高血压是一种慢性血管性疾病,易累及肾、肝、心、脑等组织,引起脑卒中和心、肾损害等并发症.本研究对高血压时肾、肝、心、脑等组织的炎症状态进行了观察.实验采用自发性高血压大鼠(spontaneously hypertensive rat,SHR)和正常血压的Wistar-Kyoto(WKY)大鼠,用RT-PCR和Western blot法观察肾、肝、心、脑等组织炎症相关因子IL-1p、TNFα、ICAM-1、iNOS、C/EBPδ和PPARγ的基因表达;紫外分光光度法观察蛋白质羰基化水平和FRAP法检测组织总抗氧化能力.结果显示(1)SHR组织炎症相关因子表达较对照WKY增强,除IL-1βmRNA在肝和脑的增加不明显外,其余均有显著性差异(P＜0.05);(2)SHR和WKY大鼠肾、心、脑蛋白质羰基化水平(nmol/mg蛋白)分别为8.93±1.08和2.27±0.43、2.23±0.23和0.17±0.02、13.42±1.10和5.72±1.01,SHR明显增加(P＜0.05);而肝脏蛋白质羰基化水平无明显变化;(3)SHR肾、肝、心、脑总抗氧化能力水平显著低于WKY大鼠(P＜0.05).以上结果表明,SHR多个组织(肾、肝、心和脑)均存在炎症因子被诱导和氧化应激反应等明显的炎症状态,提示炎症可能在高血压及其并发症的病理改变中起重要作用.     

Effects of hydrogen-rich water and ascorbic acid treatment on spontaneously hypertensive rats

Hydrogen-rich water (HW) has been suggested to possess antioxidant properties of value in treatments of lifestyle diseases and for prevention of latent pathologies. To date, the potential benefits of HW against the deleterious effects of excessive salt intake and hypertension have not been investigated. Here, we first examined the effects of HW or HW supplemented with 0.1% ascorbic acid (HWA) on spontaneously hypertensive rats (SHR) that had been fed a normal diet. In comparison to control rats given distilled water (DW), we found that HW did not significantly influence systolic blood pressure (SBP) or diastolic blood pressure (DBP) in SHR; however, the increase in SBP and DBP were inhibited in the HWA group. Next, four groups of SHR were given DW, 0.1% ascorbic acid-added DW (DWA), HW, or HWA in combination with a 4% NaCl-added diet. SHR fed the 4% NaCl-added diet showed increased hypertension; HWA treatment resulted in a significant reduction in blood pressure. The HWA group tended to have lower plasma angiotensin II levels than the DW group. In addition, urinary volumes and urinary sodium levels were significantly lower in the HWA group than the DW group. Urinary isoprostane, an oxidative stress marker, was also significantly lower in the HWA group, suggesting that the inhibitory effect of HWA on blood pressure elevation was caused by a reduction in oxidative stress. These findings suggest a synergistic interaction between HW and ascorbic acid, and also suggest that HWA ingestion has potential for prevention of hypertension.