| Objective: Left ventricular remodeling after acute myocardial infarction AMI) results in impaired function and at last heart failure. It refers to alterations in ventricular mass, chamber size and shape. The mechanisms are mainly hrough the activation of neuroendocrine and cytokine,the abnormal gene expression, which result in a series of pathological changes. Extracellular matrix remodeling exert the most prominent effect.Matrix metalloproteinases (MMPs) are a kind of foremost enzymes that degrade extracellular matrix (ECM), Transforming growth factor-β1 (TGF-β1) is one of the important cytokines that induced myocardial fibrosis, TGF-β1 are a class of cytokines with multiple function, which play an important role in the regulation of cell growth, differentiation and ECM synthesis, and are associated with fibrosis of a variety of organizations. Fasudil is a new, efficient vasodilator drugs, which can affect a variety of cell functions by blocking the Rho-kinase to protect system.This experiment is to investigate the effects of the Rho/Rho kinase inhibitors fasudil on the relationship between cytokines-matrix metalloprotei- nase-2 and transforming growth factor -β1 expression and LV remodeling after myocardial infraction.Methods: We established the left ventricular infarct in rats by ligation of the left anterior descending coronary artery. 90 healthy male Sprague Dawley rats (12-15 weeks and 210-260g) in this study were divided into Sham group (water, 2ml·d-1, intraperitoneal injection, 6), AMI group (water, 2ml·d-1 intraperitoneal injection, 6) and fasudil group (fasudil 10mg·kg-1·d-1,intraperitoneal injection after AMI 24 hours,once a day,a total of 3 weeks,6). All indexes are measured after 2 days, 7days, 14days, 21days. Myocardial infarction was detected by Evans blue-TTC staining.Westernblot was used to observe the gene expression of TGF-β1 and MMP-2 in non-infacted area . The protein expression of TGF-β1 and MMP-2 in non-infarcted area were quantified by immunohistochemical method.Results:1 Immunohistochemical staining to detect MMP-2 and TGF-β1 expression in non-infarct area and the effects of fasudil on MMP-2 and TGF-β1 expression1.1 The MMP-2 expression and the effct of fasudil on MMP-2 expression in each groupThe MMP-2 was expressed little in the sham group, and its positive part was in the endochylema.MMP-2 was activated in the AMI group, and expressed apparently more than the Sham group, the positive area in the endochylema was larger than the Sham group. In comparison with Sham group,MMP-2 was increased significantly in the AMI group and fasudil group at 2d,7d,14d and 21d (all P<0.01). In comparison with AMI group, but significantly decreased by 35.51% (P <0.01), 36.31% (P <0.01) , 29.41% (P <0.01) and 54.12% (P <0.01)respectively at 48h,7d,14d and 21d in fasudil group.1.2 The TGF-β1 expression and the effct of fasudil on TGF-β1 expression in each groupThe TGF-β1was expressed little in the sham group, and its positive part was in the endochylema. TGF-β1 was activated in the AMI group, and expressed apparently more than the Sham group, the positive area in the endochylema was larger than the Sham group.In comparison with Sham group,TGF-β1was increased significantly in the AMI group and fasudil group at 2d,7d,14d and 21d (all P<0.01). In comparison with AMI group, but significantly decreased by 29.81% (P <0.01), 36.86% (P <0.01 ), 23.54% (P <0.01) and 20.83% (P <0.01) respectively at 48h,7d,14d and 21d in fasudil group. 2 Westernblot to detect MMP-2 and TGF-β1 expression in non-infarct area after myocardial infarction and the effects of fasudil on MMP-2 and TGF-β1 expression2.1 The MMP-2 expression and the effct of fasudil on MMP-2 expression in each groupThe MMP-2 was expressed little in the sham group, and its positive part was in the endochylema.MMP-2 was activated in the AMI group, and expressed apparently more than the Sham group, the positive area in the endochylema was larger than the Sham group.In comparison with Sham group,MMP-2 was increased significantly in the AMI group and fasudil group at 2d,7d,14d and 21d (all P<0.01). In comparison with AMI group, but significantly decreased by 53.34% (P <0.01), 48.89% (P <0.01 ), 42.71% (P <0.01) and 32.69% (P <0.01) respectively at 48h,7d,14d and 21d in fasudil group.2.2 The TGF-β1 expression and the effct of fasudil on MMP-2 expression in each group:The TGF-β1was expressed little in the sham group, and its positive part was in the endochylema. TGF-β1 was activated in the AMI group, and expressed apparently more than the Sham group, the positive area in the endochylema was larger than the Sham group.In comparison with Sham group,TGF-β1was increased significantly in the AMI group and fasudil group at 2d,7d,14d and 21d (all P<0.01). In comparison with AMI group, but significantly decreased by 41.28% (P <0.01), 33.17% (P < 0.01), 26.57% (P <0.01) and 25.73% (P <0.01) respectively at 2d,7d,14d and 21d in fasudil group.3 The correlation between the protein expression of MMP-2 and TGF-β1 at different time in AMI group3.1 The correlation between the protein expression of MMP-2 and TGF-β1 at different time in AMI group by immunohistochemical method In AMI group, the relationship between between the protein expression of MMP-2 and TGF-β1at 2d,7d,14d and 21d was that MMP-2correlated positively with TGF-β1. r = 0.967, P <0.01. The regression equation was Y = 5.717 +1.024 X.3.2 The correlation between the protein expression of MMP-2 and TGF-β1 at different time in AMI group by Westernblot methodIn AMI group, the relationship between between the protein expression of MMP-2 and TGF-β1at 2d,7d,14d and 21d was that MMP-2correlated positively with TGF-β1. r = 0.987, P <0.01. The regression equation was Y = 0.097 + 0.813 X.Conclusion:1 The extracellular matrix was changed after AMI,TGF-β1 and MMP-2 expression increased in non-infarcted area,cytokines involved in development process of ventricular remodeling after myocardial infarction.2 The expression of MMP-2 correlated positively with TGF-β1 in non-infarcted area in rats with AMI.3 The use of fasudil in rats with AMI caused a reduction of expression of TGF-β1 and MMP-2 .Suggesting fasudil may be prevented LV remodeling by block the expression of TGF-β1 and MMP-2.
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