阿托伐他汀对心肌肥厚大鼠细胞外基质重塑的抑制作用

目的　探讨阿托伐他汀对去甲肾上腺素诱导的心肌肥厚大鼠细胞外基质重塑的影响及其可能的机制。方法　雄性SD大鼠随机分为三组 :(1)对照组 ,(2 )去甲肾上腺素组 [1 0 6mg/ (kg·d)× 15d],(3)去甲肾上腺素 阿托伐他汀组 [5 0mg/ (kg·d)× 15d]。去甲肾上腺素ip ,2次 /d ,15d ,建立心肌肥厚模型。应用超声心动图及病理学方法评价整体心肌肥厚及组织胶原表达。用逆转录-聚合酶链反应法 (RT PCR)及免疫组化检测细胞外基质调节因子 -基质金属蛋白酶 (MMP - 9)及其生理性抑制剂 (TIMP 1)和转化生长因子 β1(TGF - β1)mRNA和蛋白表达。结果　去甲肾上腺素组大鼠发生左心室肥厚及纤维化 ,胶原含量及MMP 9、TIMP 1和TGF - β1蛋白、mRNA表达显著高于健康对照组 (P <0 0 1)。阿托伐他汀能减少心肌中总体胶原及Ⅰ、Ⅲ型胶原的合成及MMP 9、TGF - β1表达 (P <0 0 1)。结论　MMP 9、TIMP 1和TGF - β1与心肌肥厚大鼠的细胞外基质重塑有关。阿托伐他汀能有效防治心肌纤维化及细胞外基质重塑 ,这一效应与其降低心肌中高表达的MMP 9和TGF - β1有关。     

心肌肥厚大鼠超声背向散射积分与细胞外基质重塑的相关性

目的探讨心肌肥厚大鼠背向散射积分的变化情况,并结合心肌细胞外基质的病理改变及其重要影响因子基质金属蛋白酶(MMP-9)和其生理性抑制剂(TIMP-1)在蛋白和基因水平的表达,探讨其相互关系.方法 SD大鼠腹腔注射去甲肾上腺素(1.06 mg/kg*d×15 d)建立心肌肥厚的动物模型,测定室间隔中部心肌的背向散射参数,并应用免疫组化和逆转录-聚合酶链反应法(RT-PCR)方法检测心肌总体胶原、Ⅰ型和Ⅲ型胶原的改变,及MMP-9、TIMP-1蛋白和mRNA的表达,与超声测定的结果进行对比研究.结果 (1)实验组大鼠心肌胶原成分及MMP-9、TIMP-1蛋白和mRNA的表达显著高于健康对照组(P<0.01).(2)超声背向散射积分(IBS%)在实验组较对照组增高(P<0.01),与心肌胶原、MMP-9和TIMP-1蛋白和mRNA的表达之间存在相关性.结论大鼠心肌肥厚时IBS%升高与胶原的过渡沉积密切相关,而MMP-9和TIMP-1可能是引起心肌细胞外基质重塑的重要机制之一.     

MMP-9与TGF-β1在肾性高血压大鼠心肌纤维化中的作用及阿托伐他汀的干预研究

目的探讨基质金属蛋白酶-9(MMP-9)和转化生长因子-β1(TGF-β1)在心肌纤维化中的作用及阿托伐他汀的干预研究。方法采用两肾一夹方法建立肾性高血压大鼠模型,将24只大鼠随机分为对照组、高血压组、阿托伐他汀组,每组8只。术后测量左心室重量指数(LVMI),检测心肌羟脯氨酸(HC)浓度,苦味酸-酸性品红(VG)染色检测心肌胶原容积分数(CVF),免疫组化法检测MMP-9与TGF-β1的表达水平。结果高血压组LVMI、HC、CVF与对照组比较均显著升高(P<0.01),MMP-9与TGF-β1的表达水平显著增强(P<0.01)。阿托伐他汀组较高血压组LVMI、HC、CVF均明显降低(P<0.05),MMP-9与TGF-β1的表达水平亦明显减弱(P<0.01)。结论MMP-9与TGF-β1可能与心肌纤维化的形成有关,阿托伐他汀可以抑制大鼠心肌纤维化的形成,其机制可能与降低MMP-9与TGF-β1的表达水平密切相关。     

阿托伐他汀延缓肾脏衰老机制的探讨

目的 我们的前期研究证明长期应用阿托伐他汀可以显著改善老年大鼠肾脏衰老的病理改变,本研究进一步探讨长期应用不同剂量的阿托伐他汀减轻老年大鼠肾脏衰老病理表现的机制.方法 正常20月龄Wistar雌性大鼠分为3组(每组n=9):大剂量阿托伐他汀10mg/(kg·d)灌胃;小剂量阿托伐他汀1mg/(kg·d)灌胃;等容积生理盐水灌胃,3组均连续灌胃4个月后处死大鼠(24月龄),同时以3月龄大鼠(n=9)为对照.RT-PCR方法检测大鼠肾组织内基质金属蛋白酶及其抑制剂(MMPs/TIMPs)、转化生长因子(TGF-β1)及过氧化物酶体增殖物活化型受体(PPARs)三个亚型的表达.Western印迹法检测肾组织内TIMP-1、MMP-9、TGF-β1、PPARs三个亚型的蛋白质表达.结果 老年大鼠(24月龄)较青年大鼠(3月龄)肾组织内MMP-9和TGF-β1的表达显著升高(分别为P＜0.05和P＜ 0.01),TIMPs和PPARs无显著变化.服用阿托伐他汀后显著降低MMP-9和TGF-β1的表达,升高TIMP-1、PPARα、PPARβ和PPARγ(分别为P＜ 0.01,P＜ 0.01和P＜0.05)的表达.结论 老年大鼠肾组织内MMPs/TIMPs显著失衡,TGF-β1显著高表达,老年大鼠长期应用阿托伐他汀可能通过降低MMP-9表达和增高TIMP-1表达而纠正MMPs/TIMPs的失衡状态,同时显著减低TGF-β1的表达而起到明显改善老年大鼠肾脏衰老的作用.该作用是否通过阿托伐他汀对PPARs三个亚型的激活而产生,尚需进一步的实验研究.     

基质金属蛋白酶在心肌肥厚大鼠中的作用及强力霉素的干预效果

目的:观察心肌肥厚大鼠模型中基质金属蛋白酶(MMP)-2,MMP-9及其抑制剂(TIMP-1)的表达及强力霉素干预后对其影响。方法:24只大鼠随机分为对照组(A组,只给予0.9%氯化钠溶液腹腔注射);造模组(B组)和药物干预组(C组)均用去甲肾上腺素1.06mg/kg腹腔注射,bid,注射15d,建立大鼠心肌肥厚模型,C组造模同时给予强力霉素10mg/kg腹腔注射,qd,给药15d。全部动物于给药后16d处死测定全心质量指数、左室质量指数、心肌胶原含量、心肌组织MMP-2,MMP-9,TIMP-1、心肌胶原容积分数(CVF)。结果:与A组比较,B组全心质量指数、左室质量指数、MMP-2、MMP-9阳性表达率、心肌胶原含量及CVF均明显增加(P<0.05),TIMP-1阳性表达率明显降低(P<0.05)。与B组比较,C组全心质量指数、左室质量指数、MMP-2、MMP-9阳性表达率、心肌胶原含量及CVF均明显降低(P<0.05),TIMP-1阳性表达率增加(P<0.05)。结论:去甲肾上腺素诱导的心肌肥厚大鼠MMPs/TIMPs系统平衡破坏,使基质胶原降解与合成平衡破坏,从而导致心室重构。强力霉素可通过抑制MMP来逆转心室重构。     

中药通心络对糖尿病大鼠心肌纤维化的影响

目的探讨中药通心络超微粉对糖尿病(DM)大鼠心肌纤维化的影响。方法制备大鼠DM模型并给予通心络灌胃,12 w后光镜观察病理变化检测心肌胶原容积分数(CVF),免疫组化、W estern印迹技术检测转化生长因子(TGF)-β1、基质金属蛋白酶(MMP)-9及组织型基质金属蛋白酶抑制剂(TIMP)-1蛋白表达及含量。结果与正常对照(NC)组相比,DM组CVF值明显增大,TGF-β1、MMP-9、TIMP-1蛋白表达及含量均明显升高,MMP-9/TIMP-1比值降低,TXL组上述异常均明显减轻。结论 TGF-β1、MMP-9及TIMP-1三者平衡失调可能是使DM心肌纤维化发生的机制之一,中药通心络可通过调节三者之间的平衡,有效改善DM心肌纤维化。     

比索洛尔与阿托伐他汀对高血压大鼠心肌纤维化影响的实验研究

目的探讨单独或联合应用比索洛尔与阿托伐他汀对肾性高血压大鼠心肌纤维化的影响。方法采用两肾一夹方法建立肾性高血压大鼠模型。将24只大鼠随机分为比索洛尔组、阿托伐他汀组、比索洛尔联合阿托伐他汀组,每组各8只。12周后测量左心室重量指数(LVMI),检测心肌羟脯氨酸(HC)浓度,苦味酸-酸性品红(VG)染色检测心肌胶原容积分数(CVF),免疫组化法检测基质金属蛋白酶-9(MMP-9)的表达水平。结果与治疗前相比,比索洛尔组与阿托伐他汀组血压、LVMI、HC、CVF均明显降低(P0.05)。MMP-9表达降低(P0.05),且比索洛尔组上述指标改善优于阿托伐他汀组,联合用药组较另外两组改善明显(P0.05)。结论比索洛尔与阿托伐他汀均能有效抑制大鼠心肌纤维化的形成,其机制与降低MMP-9表达水平有关,且比索洛尔疗效优于阿托伐他汀,联合用药组疗效更加明显,二者之间存在协同作用。     

酚妥拉明对心肌重构大鼠心肌细胞外基质的影响

目的　探讨酚妥拉明对去甲肾上腺素诱导大鼠心肌肥厚心肌细胞外基质（ECM）重塑的影响及可能机制。方法　24只雄性SD大鼠随机分为对照组、去甲肾上腺素造模组（模型组）和去甲肾上腺素＋酚妥拉明组（治疗组）。采用超声心动图观察心脏结构及功能变化,测定胶原容积积分（CVF）、羟脯氨酸、心肌胶原含量,用免疫组织化学法检测心肌组织基质金属蛋白酶2和胶原蛋白Ⅰ的蛋白表达。结果　模型组大鼠发生左心室肥厚,其羟脯氨酸含量、CVF值显著高于对照组（P＜0.01）,基质金属蛋白酶2和胶原蛋白Ⅰ蛋白表达上调（P＜0.01）。治疗组心肌肥大明显改善,羟脯氨酸、CVF降低,基质金属蛋白酶2和胶原蛋白Ⅰ蛋白表达下降（P＜0.05）。结论　酚妥拉明可有效减轻SD大鼠心肌肥厚的发生及ECM重塑;酚妥拉明缓解ECM重塑可能与其降低心肌组织中基质金属蛋白酶2和胶原蛋白Ⅰ的表达有关。     

中药心康方对大鼠心力衰竭模型心肌胶原代谢的影响

目的观察中药心康方对大鼠心力衰竭模型心肌胶原代谢的影响。方法阿霉素腹腔注射法建立大鼠心力衰竭模型,随机分为对照组(10只)、模型组(9只)、心康方组(9只)和卡托普利组(9只)。Masson染色观察心肌胶原变化,Western blot检测心肌Ⅰ型、Ⅲ型胶原、转化生长因子β1(TGF-β1)、核因子κB的抑制蛋白(IκB)和p56的表达,Western blot和RT-q PCR分别检测心肌基质金属蛋白酶(MMP)-2、MMP-9、基质金属蛋白酶组织抑制因子(TIMP)-1和TIMP-2的蛋白和mRNA表达水平。结果与对照组比较,模型组大鼠心肌Ⅰ型和Ⅲ型胶原表达显著增加,胶原容积分数显著升高(均为P<0.01);TGF-β1和p56表达显著增加,IκB显著降低(均为P<0.05);MMP-2、MMP-9、TIMP-1和TIMP-2的蛋白和mRNA表达水平显著升高(P<0.01或P<0.05)。与模型组比较,心康方组和卡托普利组大鼠的心肌Ⅰ型和Ⅲ型胶原表达显著减少,胶原容积分数显著降低(均为P<0.01);TGF-β1和p56显著降低,IκB显著升高(均为P<0.05);MMP-2、MMP-9、TIMP-1和TIMP-2的蛋白和mRNA表达水平显著降低(P<0.01或P<0.05)。结论中药心康方可减轻心力衰竭大鼠的心肌胶原沉积,其机制可能与抑制核因子κB介导的TGF-β1上调有关。     

他汀类药物对基质金属蛋白酶-1及组织型基质金属蛋白酶抑制剂-1的影响

目的观察阿托伐他汀(立普妥)、普伐他汀(普拉固)对大鼠腹腔巨噬细胞分泌基质金属蛋白酶-1(MMP-1)及组织型基质金属蛋白酶抑制剂-1(TIMP-1)的影响。方法培养的大鼠腹腔巨噬细胞中先加入10ng/ml的白介素-1β(IL-1β),促进MMP-1的分泌,24h后加入不同浓度的阿托伐他汀、普伐他汀(1×10-7mmol/L、1×10-6mmol/L、1×10-5mmol/L、1×10-4mmol/L),继续孵育24h后,采用酶联免疫吸附法(ELISA法)测培养上清液中的MMP-1及TIMP-1的浓度;取阿托伐他汀10-5mmol/L浓度,分别在6h、24h、48h测培养上清液中的MMP-1的浓度。结果随着药物浓度的增加(1×10-7mmol/L、1×10-6mmol/L、1×10-5mmol/L、1×10-4mmol/L),阿托伐他汀对大鼠腹腔巨噬细胞分泌MMP-1的抑制作用逐渐增强(加药组MMP-1分泌较对照组分别减少17.36%、19.40%、26.54%、33.70%),与对照组有显著统计学差异,而不同浓度的普伐他汀虽使大鼠腹腔巨噬细胞分泌MMP-1略有降低,但与对照组比较无统计学差异,且各组间也无统计学差异;两组他汀使大鼠腹腔巨噬细胞TIMP-1的分泌均略有降低,但与对照组比较,均无统计学意义;随着药物作用时间的延长(6h、24h、48h),阿托伐他汀(1×10-5mmol/L)对大鼠腹腔巨噬细胞分泌MMP-1的抑制作用逐渐增强(加药组MMP-1分泌较对照组分别减少11.96%、26.54%、32.77%),与对照组有显著统计学差异。结论阿托伐他汀呈时间剂量依赖性抑制IL-1β介导的大鼠腹腔巨噬细胞分泌MMP-1,而对TIMP-1的分泌无影响;普伐他汀对IL-1β介导的大鼠腹腔巨噬细胞分泌MMP-1无影响,对TIMP-1的分泌也无影响。     

重组转化生长因子-β3基因对大鼠肝星状细胞内、外蛋白表达的影响

目的探讨重组转化生长因子-β3（TGF-β3）基因对大鼠肝星状细胞（HSC）内、外蛋白合成及分泌的影响。方法构建质粒pcDNA3.1（＋）-TGF-β3和pcDNA3.1（＋）-TGF-β1。稳定转染：通过脂质体介导的方法,将pcDNA3.1（＋）-TGF-β1转染HSC-T6,经G418筛选建立稳定高表达pcDNA3.1（＋）-TGF-β1的HSC-T6细胞阳性克隆。再将pcDNA3.1（＋）-TGF-β3转染HSC-T6克隆细胞,用W estern b lot法和酶联免疫吸附法（ELISA）分别检测细胞内外TGF-β1、Ⅰ型胶原、基质金属蛋白酶（MMP）-2、MMP-9及金属蛋白酶组织抑制剂（TIMP）-1的蛋白表达量。结果pcDNA3.1（＋）-TGF-β3转染HSC-T6阳性细胞克隆后,与单纯阳性克隆组相比,TGF-β1、Ⅰ型胶原、TIMP-1细胞内蛋白表达及培养上清中的分泌水平均明显降低（P〈0.05）,MMP-2的表达也降低,但两者间差异无统计学意义（P〉0.05）,而MMP-9的表达明显增高（P〈0.05）。结论重组质粒pcDNA3.1（＋）-TGF-β3能减少细胞内外Ⅰ型胶原的合成及分泌;通过调节MMP-9及TIMP-1的表达,可抑制细胞外基质的合成,促进其降解。     

己酮可可碱对心肌肥厚大鼠基质金属蛋白酶2和9表达的影响

目的观察基质金属蛋白酶2和9在心肌肥厚大鼠模型中的变化,并采用己酮可可碱进行干预,以确定己酮可可碱对基质金属蛋白酶的影响及其在心肌肥厚过程中的作用。方法24只雄性SD大鼠随机分为对照组、去甲肾上腺素造模组(模型组)和去甲肾上腺素 己酮可可碱组(治疗组)。采用VG染色评价组织胶原表达,并测定心肌组织胶原含量,免疫组织化学法检测心肌组织基质金属蛋白酶2和9的蛋白表达。结果模型组大鼠发生左心室肥厚,胶原含量显著高于对照组(1.929±0.514mg/g比1.009±0.442mg/g,P<0.01);基质金属蛋白酶2和9表达(分别为131.1±9.8、125.3±4.1)显著低于对照组(P<0.01)。己酮可可碱治疗组心肌总胶原含量较模型组显著降低(1.151±0.215mg/g,P<0.01);基质中基质金属蛋白酶2和9的表达(分别为153.5±6.9、149.5±5.3)较模型组显著增高(P<0.01)。结论己酮可可碱能有效防治心肌肥厚的发生及细胞外基质重塑,这一效应可能与其降低心肌组织中基质金属蛋白酶2和9的高表达有关。     

Age-dependent changes in myocardial matrix metalloproteinase/tissue inhibitor of metalloproteinase profiles and fibroblast function

OBJECTIVE: To evaluate the effects of aging on left ventricular (LV) geometry, collagen levels, matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) abundance, and myocardial fibroblast function. METHODS: Young (3-month-old; n=28), middle-aged (MA; 15-month-old; n=17), and old (23-month-old; n=16) CB6F1 mice of both sexes were used in this study. Echocardiographic parameters were measured; collagen, MMP, and TIMP levels were determined for both the soluble and insoluble protein fractions; and fibroblast function was evaluated. RESULTS: LV end-diastolic dimensions and wall thickness increased in both MA and old mice, accompanied by increased soluble protein and decreased insoluble collagen. Immunoblotting revealed differential MMP/TIMP profiles. Compared to MA levels, MMP-3, MMP-8, MMP-9, MMP-12, and MMP-14 increased, and TIMP-3 and TIMP-4 decreased in the insoluble fraction of old mice, suggesting increased extracellular matrix (ECM) degradative capacity. Fibroblast proliferation was blunted with age. CONCLUSION: This study, for the first time, identified specific differences in cellular and extracellular processes that likely contribute to age-dependent ECM remodeling.     

Effects of inducible nitric oxide synthase inhibition in bronchial vascular remodeling-induced by chronic allergic pulmonary inflammation

Vascular remodeling is an important feature in asthma pathophysiology. Although investigations suggested that nitric oxide (NO) is involved in lung remodeling, little evidence established the role of inducible NO synthase (iNOS) isoform in bronchial vascular remodeling. The authors investigated if iNOS contribute to bronchial vascular remodeling induced by chronic allergic pulmonary inflammation. Guinea pigs were submitted to ovalbumin exposures with increasing doses (1～5 mg/mL) for 4 weeks. Animals received 1400W (iNOS-specific inhibitor) treatment for 4 days beginning at 7th inhalation. Seventy-two hours after the 7th inhalation, animals were anesthetized, mechanical ventilated, exhaled NO was collected, and lungs were removed and submitted to picrosirius and resorcin-fuchsin stains and to immunohistochemistry for matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), and transforming growth factor-β (TGF-β). Collagen and elastic fiber deposition as well as MMP-9, TIMP-1, and TGF-β expression were increase in bronchial vascular wall in ovalbumin-exposed animals. The iNOS inhibition reduced all parameters studied. In this model, iNOS inhibition reduced the bronchial vascular extracellular remodeling, particularly controlling the collagen and elastic fibers deposition in pulmonary vessels. This effect can be associated to a reduction on TGF-β and on metalloproteinase-9/TIMP-1 vascular expression. It reveals new therapeutic strategies and some possible mechanism related to specific iNOS inhibition to control vascular remodeling.     

Cardiac remodeling after long term norepinephrine treatment in rats.

OBJECTIVE: In this study we have tested the hypothesis that degradation of collagen by matrix metalloproteinase 2 (MMP-2) precedes the deposition of extracellular matrix (ECM) after long term norepinephrine (NE) treatment. METHODS: Female Sprague-Dawley rats received continuous i.v. infusion of NE (0.1 mg/kg.h) for 1, 2, 3, 4 and 14 days. Heart function and weight as well as expression of cardiac colligin and of collagen I and III were examined. Furthermore, we have assessed the degradation pathway of collagen by measuring the mRNA and activity of myocardial MMP-2 and tissue inhibitor of metalloproteinase 2 (TIMP-2) as well as the protein level of TIMP-2. RESULTS: NE induced hypertrophy predominantly of the left ventricle (LV) in a time-dependent manner. It increased the mRNAs of colligin, collagen I and III, and of MMP-2 and TIMP-2 as well as MMP-2 activity in two phases: In the initial phase, at 3 and 4 days, the mRNA of colligin and of collagen I and III was elevated predominantly in the LV, MMP-2 and TIMP-2 mRNA, as well as TIMP-2 protein and MMP-activity were increased in both ventricles. The second phase, after 14 days, was characterized by a less pronounced increase in colligin, collagen I and III and in MMP-2 activity which occurred exclusively in the LV. Finally, long-term treatment with NE induced a 37% increase in interstitial fibrosis which was shown to occur exclusively in the LV after 14 days. CONCLUSION: NE treatment induced fibrosis exclusively in the LV which was associated with hypertrophy predominantly of the LV. The elevated MMP-2 activity seems to be necessary for the ECM to adapt to the enlargement of myocytes and to reduce overproduction of collagen.     

Downregulation of vascular matrix metalloproteinase inducer and activator proteins in hypertensive patients

BACKGROUND: Peripheral vasculature undergoes extensive vascular remodeling in the hypertensive state. Regulation of extracellular matrix turnover by the matrix metalloproteinase (MMP) system is an important step in the vascular remodeling process. However, the expression pattern of the vascular MMP system in human hypertension remained unknown. METHODS AND RESULTS: Internal mammary artery specimens were obtained from normotensive (n = 13) and hypertensive (n = 19) patients undergoing coronary artery bypass grafting surgery. Zymographic analysis indicated a threefold decrease in total gelatinolytic activity of MMP-2 and MMP-9 in hypertension. MMP-1 activity was also decreased by fourfold without a significant change in protein levels. Tissue levels of extracellular matrix inducer protein (EMMPRIN), MMP activator protein (MT1-MMP), MMP-1, MMP-2, and MMP-9, as well as tissue inhibitors of MMPs (TIMP-1 and TIMP-2) were assessed by immunoblotting and yielded a significant decrease in MMP-9, EMMPRIN, and MT1-MMP levels in hypertension. In addition, measurement of plasma markers of collagen synthesis (procollagen type I amino-terminal propeptide [PINP]) and collagen degradation (carboxy-terminal telopeptide of collagen type I [ICTP]) indicated no difference in PINP levels but suppressed degradation of collagen in hypertension. Evaluation of profibrotic growth factors demonstrated higher levels of fibroblast growth factor (FGF)-2 in tissue preparations from hypertensive patients but no difference in transforming growth factor-beta1 levels. CONCLUSIONS: These findings demonstrate that not only MMP-1 and MMP-9, but MMP inducer and activator proteins are also downregulated in the hypertensive state. Augmented FGF-2 levels may contribute to parallel decreases in MMP activity and MMP induction system resulting in enhanced collagen deposition in hypertension.     

基质金属蛋白酶及抑制剂在心肌梗死后心室重构中的作用

目的　研究大鼠心肌梗死后外源性基质金属蛋白酶抑制剂 (多西环素 ,Doxycycline)在心室重构中的作用。方法　 70只SD大鼠随机分为对照组 (10只 )、手术对照组 (9只 )、心肌梗死后 1天组 (10只 )、心肌梗死后 1周组 (10只 )、心肌梗死后 2周组 (8只 )、心肌梗死后 4周组 (7只 )、治疗 2周组 (8只 )和治疗 4周组 (8只 ) ,采用免疫组织化学、酶谱法、免疫印迹 (WesternBlotting)、逆转录 聚合酶链反应 (RT PCR)和AcusonSequoia 5 12超声心动图仪分别测定胶原含量 ,Ⅰ Ⅲ胶原比例、基质金属蛋白酶 2 ,9(MMP 2 ,9)蛋白和mRNA的变化规律及心功能。结果　多西环素治疗后 ,胶原含量明显减少 ,Ⅰ Ⅲ胶原比例下降得以改善 (P <0 .0 5 ) ,MMP 2 ,9蛋白和mRNA在心肌梗死后活性减少 ,基质金属蛋白酶组织抑制剂 1蛋白含量和mRNA转录无明显变化 ,治疗组心功能在术后 4周得以改善。结论　多西环素治疗后MMP 2 ,9的mRNA转录减少 ,MMP 2 ,9活性降低 ,胶原含量减少 ,Ⅰ Ⅲ胶原比例恢复 ,这些影响可能是其改善心肌梗死后心室重构的机制之一。     

辛伐他汀改善心肌梗死后心肌胶原含量变化及机制的实验研究

目的:探讨辛伐他汀对大鼠心肌梗死后心肌胶原含量的影响及其机制. 方法:建立大鼠心肌梗死模型,24 h后存活大鼠随机分成心肌梗死组(n=9)、辛伐他汀20 mg组[20 ms/(kg·d),n=10]和平伐他汀40 mg组[40 ms/(kg·d),n=9],另设假手术组(n=10).4周后观察血脂水平、左心室重指数和天狼猩红染色分析左心室非梗死区心肌胶原容积分数(表达心肌胶原含量),免疫组化检测基质金属蛋白酶-2(MMP-2),免疫印迹杂交方法(Western blot)和逆转录多聚酶链反应(RT-PCR)检测转化生长因子β1(TGF-β1)在非梗死区的表达. 结果:①各组血脂水平差异无统计学意义,心肌梗死组左心室重苗指数、非梗死区Ⅰ型、Ⅲ型胶原容积分数及Ⅰ型与Ⅲ型胶原容积分数比值较假手术组均明显升高(P均<0.05),差异均有统计学意义;辛伐他汀两组左心室重量指数、非梗死区Ⅰ型、Ⅲ型胶原容积分数及Ⅰ型与Ⅲ型胶原容积分数比值较心肌梗死组均卜降,但仍高于假手术组(P均<0.05),差异均有统计学意义.②心肌梗死组MMP-2和TGF-β1表达较假手术组均显著增加(P均<0.05),而辛伐他汀两组表达则明显降低,但仍高于假手术组(P均<0.05),差异均有统计学意义. 结论:辛伐他汀能有效改善大鼠心肌梗死后心肌胶原含量,机制与其渊脂作用无关,可能与下调MMP-2和TGF-β1的表达有关.     

Matrix metalloproteinase-9 and tissue inhibitor metalloproteinase-1 levels in essential hypertension. Relationship to left ventricular mass and anti-hypertensive therapy

To test the hypothesis that the activity of enzymes degrading the extracellular matrix in hypertensive patients are abnormal, and that the treatment of hypertension will normalise these abnormalities, we measured the serum levels of metalloproteinase MMP-9, and its inhibitor, tissue metalloproteinase inhibitor (TIMP-1). Thirty-two patients with untreated hypertension (BP 168/96) had significantly lower levels of both MMP-9 and TIMP-1 when compared to 24 matched normotensive controls (BP 123/80) (P<0.001). There was no significant correlation between MMP-9 and TIMP-1 levels (P>0.2). In the patients, there were no significant correlations observed between left ventricular mass, Doppler V(E)/V(A) ratio (an index of diastolic function), blood pressure, left ventricular mass index and either MMP-9 or TIMP-1 levels (all P=NS). Levels of MMP-9 and TIMP-1 were not significantly altered after 2 months of antihypertensive treatment of 29 patients despite mean blood pressure falling from 170/96 to 143/85 mmHg (P<0.001). Correspondingly, there were also no significant alterations in indices of diastolic function and left ventricular mass. Our study suggests that the proteolytic activities of MMP-9 and TIMP-l are depressed in hypertensive patients and were not significantly affected by short-term antihypertensive treatment. The relationship between collagen metabolism in hypertensive subjects, especially in those with cardiac hypertrophy, and the effects of treatment needs to be further explored in larger trials over a longer period of time.