多西环素逆转阿霉素心肌病大鼠心脏间质纤维化的实验研究

目的研究基质金属蛋白酶抑制剂多西环素对阿霉素心肌病大鼠心脏间质纤维化的逆转作用及其机制。方法60只♂Wistar大鼠分3组:①阿霉素心肌病组(ADR-DCM,n=25),阿霉素2.5mg.kg-1,尾静脉注射,每周1次,连续10wk;②阿霉素心肌病+多西环素治疗组(DOX,n=25),DOX30mg.kg-1,每天1次,灌胃治疗;③正常对照组(CON,n=10)。于实验第12wk时氯胺T法检测羟脯氨酸及胶原含量,苦味酸天狼猩红染色进行左室胶原特异染色及定量分析,计算胶原容积分数(CVF),并作HE染色观察其组织学变化,明胶酶谱法检测基质金属蛋白酶(MMPs)活性。结果DOX组较ADR-DCM组死亡率明显降低(16%vs40%,P<0.01)。与CON组相比,ADR-DCM组羟脯氨酸及胶原含量增加(P<0.01),经DOX治疗后有所减低。苦味酸天狼猩红染色显示ADR-DCM组左室胶原明显增加,胶原容积分数(CVF)明显增高(P<0.01),而DOX组则纤维化明显减轻,CVF降低(P<0.01)。病理学结果证实ADR-DCM组符合心肌病样改变,而DOX组可逆转这种改变。ADR-DCM组左室心肌MMPs明胶酶活性明显增加(P<0.01),DOX组明显降低升高的MMPs明胶酶活性(P<0.01)。结论多西环素通过抑制MMPs活性部分逆转阿霉素心肌病大鼠心脏间质纤维化。

Doxycycline, a nonspecific matrix metalloproteinase inhibitor protects the adriamycin-induced dilated cardiomyopathy rat against myocardial interstitial fibrosis

Aim To investigate whether doxycycline,a nonspecific matrix metalloproteinase inhibitor could reverse myocardial interstitial fibrosis in a rat model of adriamycin-induced dilated cardiomyopathy.Methods Sixty Weight-matched Adult male Wistar rats were randomly divided into 3 groups as follows:① the ADR-DCM group,in which 2.5 mg·kg-1 of adriamycin(ADR)was weekly injected via a tail vein for 10 weeks(n=25);② the DOX group,concomitant doxycycline and ADR,in which DOX as a nonspecific matrix metalloproteinase inhibitor was administered by daily gavage at a dose of 30 mg·kg-1·d-1(n=25);③ the control group(n=10).The hydroxyproline and collagen content were determined by the methods of chloraminesT at 12 weeks after treatment.The expression and distribution of collagen in LV were investigated with Picric acid-Sirius red staining techniques.Semi-quantitative analysis was used to evaluate the collagen volume fraction(CVF).The pathological change was analyzed by histological hematoxylin-eosin staining.LV myocardial MMP-2 and MMP-9 gelatinolytic activities were measured by gelatin zymography.Results Mortality was significantly lower for DOX-treated rat than that for ADR-DCM group(16% versus 40%,P<0.01).The hydroxyproline content was increased in ADR-DCM group and was significantly reduced by doxycycline treatment(P<0.01).LV myocardial collagen was increased and myocardial fibrosis occurred,LV collagen volume fraction(CVF)was increased significantly in ADR-DCM group,which was partly reversed by doxycycline treatment(P<0.01).Doxycycline attenuated the pathological changes of cardiomypathy induced by ADR.LV myocardial MMP-2 and MMP-9 gelatinolytic activities were increased significantly in in ADR-DCM group(P<0.01)and attenuated by doxycycline treatment(P<0.01).Conclusion Pretreatment with doxycycline could partly reverse myocardial interstitial fibrosis in a rat model of adriamycin-induced dilated cardiomyopathy by inhibiting the gelatinolytic activities.