PDGF-AA对血管平滑肌细胞c-myc、c-myb mRNA及PCNA表达的影响

目的明确血小板源生长因子-AA(PDGF-AA)与自发性高血压大鼠血管平滑肌细胞(SHR-VSMC)增殖的关系.方法采用Western blot、RT-PCR等方法,观察在SHR和Wistar大鼠VSMC中,PDGF-AA对SHR/Wistar-VSMC增殖细胞核抗原(PCNA)、c-myc、c-myb mRNA表达影响的差异性.结果在不同浓度PDGF-AA刺激下,SHR-VSMC中PCNA、c-myc、c-myb mRNA表达明显高于Wistar-VSMC(P＜0.01),且呈明显的剂量依赖性关系(P＜0.01).结论PDGF-AA特异性的刺激SHR-VSMC异常增殖,可能是导致高血压血管重构的重要原因之一.     

雌激素对培养的兔平滑肌细胞增殖与移行的影响

目的: 探讨雌激素对培养的兔平滑肌细胞增殖与移行的影响。方法: 分别测定不同浓度雌激素作用下兔血管平滑肌细胞[³H]-TdR掺入量、增殖细胞核抗原(PCNA)的表达、血管平滑肌细胞(VSMC)移行的变化。结果: 低浓度(1 nmol/L)的雌激素组的培养细胞[³H]-TdR掺入量及VSMC平均光密度值、VSMC移行细胞数与对照组相比无明显差异(P>0.05), 较高浓度(10 nmol/L、100 nmol/L)的雌激素可以显著降低培养的[³H]TdR掺入量及培养VSMC平均光密度值, 并能显著减少VSMC移行细胞数目(P<0.01)。结论: 雌激素可抑制血管平滑肌细胞的增殖与移行, 从而发挥抗动脉粥样硬化作用。     

氟伐他汀抑制高血压大鼠血管平滑肌细胞增殖

目的:探讨氟伐他汀对自发性高血压大鼠血管平滑肌细胞增殖的抑制作用。方法:培养自发性高血压大鼠主动脉血管平滑肌细胞,不同浓度血管紧张素Ⅱ(AngⅡ)、血小板源生长因子(PDGF)、氟伐他汀及甲羟戊酸干预后,行细胞计数和[³H]-TdR掺入率测定。结果:①氟伐他汀呈浓度依赖性抑制10^-6mol/LAngⅡ和10μg/LPDGF刺激诱导的血管平滑肌细胞数和[³H]-TdR掺入率增加;②10^-3mol/L甲羟戊酸几乎完全逆转氟伐他汀对血管平滑肌细胞增殖的抑制作用。结论:氟伐他汀抑制AngⅡ和PDGF诱导的高血压大鼠血管平滑肌细胞增殖;甲羟戊酸代谢途径可能参与血管平滑肌细胞增殖过程。     

瓜蒌注射液对兔血管平滑肌细胞增殖细胞核抗原表达的影响

目的:观察瓜蒌注射液对血管平滑肌细胞(SMC)增殖细胞核抗原(PCNA)表达的影响。方法:用免疫组织化学LSAB法检测培养的兔主动脉SMC中PCNA的表达,液闪法测定SMC氚-胸腺嘧啶核苷([³H]-TdR)掺入量,同时测定培养液中超氧化物歧化酶(SOD)、脂质过氧化物(LPO)、前列环素(PGI₂)及环磷酸腺苷(cAMP)的含量。结果:瓜蒌注射液能增加SOD活性,降低LPO和升高PGI₂、cAMP水平,抑制SMC的[³H]-TdR掺入量和PCNA的表达(P均＜0.05,0.01)。结论:瓜蒌有抑制SMC增殖的作用。     

肾上腺素在心肌细胞肥大中的作用

目的：探讨肾上腺素在心肌细胞肥大中的作用。方法：在培养新生大鼠心肌细胞上,通过测量心肌细胞[³H]-Leu的掺入量来判断心肌细胞肥大。结果：肾上腺素能明显增加心肌细胞[³H]-Leu的掺入量,酚妥拉明、心得安、百日咳毒素（PTX）和蛋白激酶C（PKC）抑制剂（calphostin C）均可抑制肾上腺素诱导的心肌细胞[³H]-Leu掺入量增加。结论：肾上腺素诱导的心肌细胞肥大反应与激动肾上腺能受体（α受体和β受体）有关,并通过G蛋白和PKC起作用。     

3种钙激动剂促培养的大鼠血管平滑肌细胞增殖

目的：探讨不同来源的细胞内钙离子（[Ca²⁺]i）对血管平滑肌细胞（vascular smooth muscle cells, VSMCs）丝裂素活化蛋白激酶（MAPK）介导的增殖反应的作用。方法：以培养的大鼠VSMCs为靶细胞,用血管紧张素II（Ang Ⅱ）剌激VSMCs跨膜Ca²⁺内流、三磷酸肌醇（IP₃）和雷尼丁（RY）剌激胞内Ca²⁺释放,[γ-³² P]-ATP掺入法和免疫印迹（Western blot）测MAPK活性及蛋白含量,氚-亮氨酸（[³H]-Leu）、氚-胸腺嘧啶（[³H]-TdR）掺入量作为VSMCs增殖的指标。结果：Ang Ⅱ、IP₃和RY均能显著增加VSMCs的[Ca²⁺]i浓度、MAPK活性及蛋白含量,并提高[³H]-Leu、[³H]-TdR掺入量,与对照组VSMCs相比差异显著（P<0.01）。结论：钙激动剂诱导的MAPK活性及含量的增加参与了VSMCs的增殖,VSMCs的肥大增殖与[Ca²⁺]i浓度增加有关,而与[Ca²⁺]i的来源无关。     

金属硫蛋白抑制同型半胱氨酸诱导的大鼠血管平滑肌细胞增殖

目的:研究金属硫蛋白(MT)对同型半胱氨酸(Hcy)诱导大鼠血管平滑肌细胞(vascularsmoothmusclecells,VSMCs)增殖的影响及其作用机制。方法:以[³H]-TdR掺入法测定VSMCs增殖程度,免疫沉淀法测定VSMCs内丝裂素活化蛋白激酶(MAPK)活性,[¹⁰⁹Cd]-血红蛋白饱和法测定MT含量,硫代巴比妥酸法测定丙二醛(MDA)含量,NADH氧化法测定乳酸脱氢酶(LDH)漏出量。结果:Hcy(10^-6-10^-4mmol/L)呈浓度依赖性的刺激培养大鼠VSMCs[³H]-TdR掺入,0.1mmol/LHcy刺激[³H]-TdR掺入比对照组高4.2倍(P＜0.01)。Hcy亦呈浓度依赖性地激活VSMCsMAPK活性、增加细胞MDA的生成和LDH的漏出(P均<0.01)。单独MT孵育,对VSMCs的上述指标均无明显影响(P＞0.05)。但MT(10^-6-10^-4mol/L)呈浓度依赖性抑制100μmol/LHcy的促增殖效应(r=0.98,P＜0.01)。MT显著抑制Hcy对VSMCs的MAPK活性、MDA生成和LDH漏出的激活作用(均P＜0.01)。以0.5mmol/LZnCl₂预孵育6h后,VSMCsMT含量比非诱导细胞高5.7倍(P＜0.01),这种内源性MT高表达的细胞,显著抵抗Hcy刺激的-TdR掺入和MAPK激活;抑制Hcy的促细胞MDA生成与LDH漏出效应(均P＜0.01)。结论:MT能有效抑制Hcy促大鼠VMSCs增殖作用,其机制可能与MT拮抗Hcy对MAPK的激活和其抗氧化作用有关。     

同型半胱氨酸对气道平滑肌细胞及成纤维细胞的影响

目的:探讨同型半胱氨酸(HCY)对气道平滑肌细胞及成纤维细胞的增殖和成纤维细胞胶原生成的影响。方法:在培养的兔气道平滑肌细胞和大鼠成纤维细胞上,用[³H]-胸腺嘧啶和[³H]-脯氨酸掺入方法观察不同浓度HCY对细胞增殖和成纤维细胞胶原生成的影响。 结果:HCY(0.1~1.0 mmol/L)呈浓度依赖性刺激气道平滑肌细胞和成纤维细胞增殖,并呈浓度依赖性刺激气道成纤维细胞的胶原合成与分泌。蛋白激酶C抑制剂H7及多粘菌素B可抑制HCY诱导的气道平滑肌细胞增殖。 结论:HCY刺激气道平滑肌 细胞及成纤维细胞增殖,并促进成纤维细胞的胶原合成和分泌。HCY刺激气道平滑肌细胞增殖可能通过PKC信号传导途径。     

188铼辐射抑制血管平滑肌细胞增殖研究

目的：探讨放射性核素¹⁸⁸铼（¹⁸⁸Re）对培养平滑肌细胞增殖的作用及其机制。方法：应用¹⁸⁸Re β射线进行培养平滑肌细胞的内辐射。通过细胞计数、再增殖试验、[³H]-TdR掺入试验、流式细胞术细胞周期分析、免疫细胞化学及细胞存活率检测等方法,观察辐射抑制平滑肌细胞增殖的有效及最佳剂量、有效抑制时间、细胞增殖率变化、细胞周期分布、细胞存活率及其相关基因表达。结果：5.2 Gy剂量辐射,50%以上平滑肌细胞增殖受抑,细胞增殖率为46%;20.6 Gy剂量辐射,DNA合成抑制率达92%,增殖期细胞占3%;辐射后2周未见细胞再增殖,<20.6 Gy辐射未见细胞存活力下降;辐射后P53表达升高,PCNA表达降低。结论：¹⁸⁸Re β辐射对平滑肌细胞增殖抑制有效且持久半数有效剂量为5 Gy最佳辐射剂量为20 Gy。低剂量辐射抑制平滑肌细胞增殖的主要机制为损伤细胞分裂增殖能力。P53及PCNA调控辐射抑制细胞增殖过程。     

养血清脑血清拮抗溶血磷脂酸诱导大鼠血管平滑肌细胞增殖

目的:观察养血清脑药物血清对溶血磷脂酸(LPA)诱导的大鼠血管平滑细胞(VSMC)增殖作用的影响。方法:在培养的大鼠平滑肌细胞上,测定[³H]-胸腺嘧啶核苷([³H]-thymidine,[³H]-TdR)掺入、丝裂素活化蛋白激酶(mitogen-activated protein kinase,MAPK)活性及脂质过氧化终产物丙二醛(malonyldialdehyde,MDA)含量。结果:1×10^－9、1×10^－8和1×10^－7 mol·L^-1 LPA呈浓度依赖性引起VSMC[³H]-TdR掺入量、MAPK活性及MDA含量增加。5％、10％和15％养血清脑血清预孵育使1×10^－7 mol·L^-1 LPA诱导VSMC[³H]-TdR掺入量分别下降23.0％、42.0％和52.0％(P<0.01);使VSMC MAPK的活性分别下降13.9％(P<0.05)、29.6％(P<0.01)和48.9％(P<0.01);使细胞MDA含量分别下降19.4％、24.7％和43.2％(P<0.01)。结论:LPA呈浓度依赖性引起VSMC增殖及脂质过氧化,VSMC增殖与其细胞内信号转导MAPK途径有关。养血清脑血清可有效地拮抗LPA诱导的VSMC增殖、MAPK激活和脂质过氧化损伤。     

The effects of anti-hypertensive therapy on the structural,mechanical and metabolic properties of the rat aorta

The vascular system exhibits altered growth, calcium responses and metabolism during hypertension. To relate such changes, we compared histological, tension and metabolic responses in the aorta from 32-week-old spontaneously hypertensive rats (SHRs), normotensive Wistar–Kyoto (WKY) rats, and SHRs treated with Verapamil (V) and ACE-inhibitor, Trandolapril (T) as well as a combination of the two treatments (C). Vascular hypertrophy was apparent in the SHRs. Contractile responses induced by 50 mmol/l KCl and 2.5 mmol/l Ca²⁺ were significantly lower in the SHR (64.4 mN/mm² vs. 49.2 mN/mm²), but an associated increase in Ca²⁺-sensitivity (EC₅₀ of extracellular Ca²⁺ (mol/l): SHR, 456 vs. WKY, 616) normalised tension generating ability. All treatments led to significant decreases in blood pressure, although only T and C treated animals became normotensive with concomitant normalisation of vascular hypertrophy. An increase in oxygen consumption was apparent in the SHR aorta, which was associated with significant differences in the activities of key metabolic enzymes. Anti-hypertensive treatment normalised many of the metabolic parameters, with the C therapy being the most efficacious. We conclude that the treatment of hypertension by combined therapy leads to a better normalisation of structural, contractile, and metabolic parameters in the SHR, than either treatment alone and that metabolic changes with the pathology are resolved with appropriate therapy.     

不同年龄高血压大鼠血管平滑肌中ERK和MKP-1的表达

目的：研究不同年龄的自发性高血压大鼠（SHR）和Wistar Kyoto大鼠（WKY）主动脉平滑肌中丝裂原活化蛋白激酶（MAPK）及其磷酸酶（MKP-1）的表达及其与高血压的关系。 方法： 用tail-cuff测量大鼠尾动脉血压；分别用Western blotting法和RT-PCR法半定量测定血管平滑肌中磷酸化细胞外信号调节激酶（p-ERK）和MKP-1的蛋白表达以及MKP-1 mRNA的含量。 结果： （1）SHR的血压自8周龄起明显高于WKY（P<0.01），且随年龄增长而升高（P<0.05）至14周以后趋于稳定；（2）SHR主动脉平滑肌中的p-ERK表达明显高于同年龄的WKY（P<0.01），随年龄增长而递增（P<0.05），与血压呈正相关；（3）SHR主动脉平滑肌中MKP-1蛋白明显高于同龄WKY，而mRNA的表达在5周龄时明显高于WKY，之后均随年龄的增长而递减（P<0.05），与血压和ERK呈负相关，而WKY下降不明显。 结论： MKP-1在高血压的发生和发展过程中起重要作用，其表达逐渐下降可能是导致ERK激活增加，从而导致血管平滑肌细胞增殖、血压升高的重要原因。     

El factor de crecimiento del hepatocito disminuye la expresión vascular de mediadores inflamatorios y la hipertensión en ratas espontáneamente hipertensas

Objective

This study was designed to examine the effects of hepatocyte growth factor (HGF) gene delivery on vascular inflammation and hypertension in spontaneously hypertensive rats (SHR). We speculated that HGF deficiency could play a key role in the pathogenesis of hypertension in SHR, and that increasing HGF levels will produce prolonged decreases in blood pressure due to reduced vascular inflammation.

Materials and methods

Fifteen-week old male SHRs received weekly hydrodynamic injections of a naked plasmid containing human HGF (pCMV-HGF) (1 mg/kg) or empty vector (pcDNA3.1) for 6 weeks. Two groups of Wistar-Kyoto (WKY) rats were used as controls (n = 6) and treated in the same manner. The activation of NF-κB was assessed by Western blot and mRNA expression of pro-inflammatory cytokines by real-time PCR and Western blot.

Results

Blood pressure, NF-κB activation and expression of IL-6, MCP-1 and RANTES were significantly higher in SHR than in the control WKY. The HGF gene therapy normalized NF-κB activity, pro-inflammatory cytokines expression, and decreased the hypertension in SHR.

Conclusion

These observations suggest that decreased aorta HGF concentration may have a role in the vascular inflammation observed in SHR, and demonstrate that increasing HGF is a potential therapeutic target in the treatment of hypertension.     

Angiotensin-converting enzyme 2 activation protects against hypertension-induced cardiac fibrosis involving extracellular signal-regulated kinases

Our previous studies have indicated that chronic treatment with 1-[(2-dimethylamino) ethylamino]-4-(hydroxymethyl)-7-[(4-methylphenyl) sulfonyl oxy]-9H-xanthene-9-one (XNT), an angiotensin-converting enzyme 2 (ACE2) activator, reverses hypertension-induced cardiac and renal fibrosis in spontaneously hypertensive rats (SHRs). Furthermore, XNT prevented pulmonary vascular remodelling and right ventricular hypertrophy and fibrosis in a rat model of monocrotaline-induced pulmonary hypertension. The aim of this study was to determine the mechanisms underlying the protective effects of XNT against cardiac fibrosis. Hydroxyproline assay was used to measure cardiac collagen content in control and XNT-treated (200 ng kg(-1) min(-1) for 28 days) SHRs. Cardiac ACE2 activity and protein levels were determined using the fluorogenic peptide assay and Western blot analysis, respectively. Extracellular signal-regulated kinases (ERKs; p44 and p42) and angiotensin II type 1 (AT(1)) receptor levels were quantified by Western blotting. Cardiac ACE2 protein levels were ～15% lower in SHRs compared with Wistar-Kyoto control animals (ACE2/glyceraldehyde 3-phosphate dehydrogenase ratio: Wistar-Kyoto, 1.00 ± 0.02 versus SHR, 0.87 ± 0.01). However, treatment of SHRs with XNT completely restored the decreased cardiac ACE2 levels. Also, chronic infusion of XNT significantly increased cardiac ACE2 activity in SHRs. This increase in ACE2 activity was associated with decreased cardiac collagen content. Furthermore, the antifibrotic effect of XNT correlated with increased cardiac angiotensin-(1-7) immunostaining, though no change in cardiac AT(1) protein levels was observed. The beneficial effects of XNT were also accompanied by a reduction in ERK phosphorylation (phospho-ERK/total ERK ratio: Wistar-Kyoto, 1.00 ± 0.04; control SHR, 1.46 ± 0.25; treated SHR, 0.86 ± 0.02). Our observations demonstrate that XNT activates cardiac ACE2 and inhibits fibrosis. These effects are associated with increases in angiotensin-(1-7) and inhibition of cardiac ERK signalling.     

Changes of imidazoline receptors in spontaneously hypertensive rats

The role of imidazoline receptors in the regulation of vascular function remains unclear. In this study, we evaluated the effect of agmatine, an imidazoline receptor agonist, on systolic blood pressure (SBP) in spontaneously hypertensive rats (SHRs) and investigated the expressions of imidazoline receptors by Western blot. The isometric tension of aortic rings isolated from male SHRs was also estimated. Agmatine decreased SBP in a dose‐dependent manner in SHRs but not in the normal group [Wistar–Kyoto (WKY) rats]. This reduction in SBP in SHRs was abolished by BU224, a selective antagonist of imidazoline I₂‐receptors. Higher expression of imidazoline receptors in SHR was observed. Moreover, agmatine‐induced relaxation in isolated aortic rings precontracted with phenylephrine or KCl. This relaxation was also abolished by BU224 but was not modified by efaroxan, an imidazoline I₁‐receptor antagonist. Agmatine‐induced relaxation was also attenuated by PNU 37883, a selective blocker of vascular ATP‐sensitive potassium (K_ATP) channels. Additionally, vasodilatation by agmatine was reduced by an inhibitor of protein kinase A (PKA). We suggest that agmatine can lower blood pressure in SHRs through activation of the peripheral imidazoline I₂‐receptor, which is expressed more highly in SHRs.     

螺内酯和缬沙坦对高血压大鼠心肌细胞外信号调节激酶的影响

目的:观察血管紧张素Ⅱ受体拮抗剂缬沙坦和醛固酮受体拮抗剂螺内酯对SHR心肌中活化的ERK的影响。方法:将18只雄性SHR随机分为三组,每组6只。其中两组分别用缬沙坦30mg/kg/天、螺内酯20mg/kg/天溶于饮水灌胃,连续治疗13周;对照组给正常饮水,并与Wist-ar-kyoto大鼠(WKY)比较。用Western-blot方法检测大鼠心肌磷酸化ERK的表达。结果:SHR对照组心肌磷酸化ERK/actin值高于其余三组(P<0.01),螺内酯和缬沙坦组高于WKY组(P<0.01),两用药组之间无差异。结论:血管紧张素Ⅱ受体拮抗剂缬沙坦和醛固酮受体拮抗剂均能通过抑制ERK途径而抑制左室肥厚和心肌纤维化。     

Temporal characteristics of cardiomyocyte hypertrophy in the spontaneously hypertensive rat.

BACKGROUND: The spontaneously hypertensive rat (SHR) is frequently used as model of cardiovascular disease, with considerable disparity in reported parameters of hypertrophy. The aim of this study was to assess the temporal changes occurring during the development and progression of cardiomyocyte hypertrophy in SHR, subsequent to pressure overload, compared to changes associated with normal aging using the normotensive Wistar-Kyoto (WKY) rat. METHODS: Ventricular cardiomyocytes were isolated from rats at 8, 12, 16, 20 and 24 weeks, and parameters of hypertrophy (cell dimensions, protein mass, de novo protein synthesis, and gene expression) and function (contraction and hypertrophic responsiveness in vitro) were assessed. RESULTS: Hypertension was evident at > or =7 weeks in SHRs. Heart:body mass ratio, cardiomyocyte protein mass and width were elevated (P<.05) in SHRs at 16-20 weeks compared to WKYs. In SHRs compared to WKYs at 16 weeks, there was a transient increase (P<.05) in protein synthesis, enhanced hypertrophic responsiveness to phorbol-12-myristate-13-acetate, and induced hypertrophic responsiveness to isoprenaline. Skeletal-alpha-actin mRNA was detected in SHR but not WKY cells at all ages. ANP mRNA was lower in SHR than in WKY cells at 8-20, but progressively increased (P<.05) from 12 to 24 weeks within SHRs. Contractile function increased (P<.05) at 20 weeks in SHR compared to WKY rats. CONCLUSION: Structural and functional changes occurring at the cellular level in the myocardium of SHR follow a distinct pattern, such that pressure overload was initially accompanied by expressional changes (8-12 weeks), followed by active hypertrophic growth and enhanced function (16-20 weeks), which subsequently decelerated as stable compensation was attained.     

自发性高血压大鼠淋巴微循环功能受损

目的:观察自发性高血压大鼠(SHRs)淋巴微循环功能变化.方法:8周龄雄性SHR大鼠(SHR组)和WKY大鼠(WKY组),每组各10只.应用VasT rack测量两组大鼠微淋巴管自律运动;取胸导管分离原代淋巴管内皮细胞(LECs).应用免疫荧光和Western Blot检测LECs血管内皮生长因子受体3(VEGFR3)...     

三七总皂苷通过Notch3/Hes-1/p27Kip1信号通路抑制低氧性肺动脉高压大鼠肺血管重构

目的：探讨Notch3/Hes-1/p27^Kip1信号通路与低氧性肺动脉高压大鼠肺血管重构的关系及三七总皂苷(PNS)的干预作用。方法：将SPF级雄性SD大鼠采用随机编号分为3组：正常组(C组),低氧组(H组)和PNS组(P组),检测肺动脉压,称量右心室重量,HE染色和Masson染色观察肺血管重构情况,RT-qPCR检测大鼠肺组织中Notch3、Hes-1和p27^Kip1的mRNA表达水平,Western blot检测大鼠肺组织中Notch3、Hes-1、p27^Kip1,增殖细胞核抗原(PCNA)和caspase-3的蛋白水平。结果：与C组相比,H组大鼠的肺动脉压和右心室肥厚指数明显增加;肺血管重构现象明显;Notch3、Hes-1和PCNA的蛋白水平增加,p27^Kip1和caspase-3的蛋白水平降低;Notch3和Hes-1的mRNA表达增加,p27^Kip1的mRNA表达降低(P<0.05)。经PNS干预后,与H组相比,P组大鼠的肺动脉压和右心室肥厚指数降低;肺血...     

纤维粘连蛋白对培养的自发性高血压大鼠心肌成纤维细胞增殖及胶原合成的影响

目的:观察纤维粘连蛋白(FN)对培养的SHR和WKY大鼠心肌成纤维细胞(CFb, CFb_SHR, CFb_WKY)增殖及胶原合成的影响。方法:CFb取自12周的SHR和WKY大鼠, 采用组织块贴壁法培养, 以直接细胞计数法和 [³H]-TdR掺入率反映细胞增殖, 以[³H]-脯氨酸([³H]-proline)掺入率反映胶原合成。使用FN(5 μg/cm²)预先处理24孔培养板。 结果: 与0.4% FCS对照组相比, 经72 h孵育FN明显促进CFb_SHR和CFb_WKY细胞数增多, 分别为对照组的163.75%(CFb_SHR)和170.42%(CFb_WKY)。FN促进CFb_SHR和CFb_WKY [³H]-TdR掺入增加。FN促进CFb_SHR和CFb_WKY[³H]-proline掺入增加。 结论:FN促进SHR和WKY大鼠的CFb增殖及胶原合成。