Effect Of Short-term Atorvastatin Calcium Preconditioning On Matrix Metalloproteinases During Myocardial Reperfusion In Rabbits

Objective:This experimental study was undertaken to explore effects of short-term pretreatment with atorvastatin calcium on Matrix Metalloproteinases(MMPs) during myocardial reperfusion in rabbits and to investigate potential mechanism of cardioprotection during reperfusion.Methods:We occluded left anterior descending coronary artery in rabbits followed traditional methods to build myocardial reperfusion injury model.Animal in experiment:Fifty New-Zealand rabbits; Group of experiment:Fifty New-Zealand rabbits were divided into five group randomly: Normal control group(n=10), placebo group( n=10 , before operation procedure,to give placebo 4mg/kg.d * 3 days),Atorvastatin calcium group(n=10, before operation procedure,to give atorvastatin 4mg/kg.d * 3 days), Perindopril group(n=10, before operation procedure,to give perindopril 0.2mg/kg.d * 3 days) ,and Atorvastatin calcium combine Perindopril group(n=10, before operation procedure,to give atorvastatin 4mg/kg.d * 3 days and perindopril 0.2mg/kg.d * 3 days). After the procedure,the rabbits'heart were underwent to make TTC staning in order to observe the area of myocardium ischeamia and myocardial infarction, the histochemistry staining and RT-PCR measurements were used to evaluate the expression of MMP-2,MMP-9,TIMP-2 in rabies myocardium in our experiment.Results:1. TTC staning1.1 The percent of Myocardium ischemia areas(the left ventricular ischemia dangerous areas/the total areas of left ventricular),Myocardium ischemia areas in the reperfusion models were more higher than in normal control model;placebo group(38.61+1.53),atorvastatin calcium group (37.5 + 1.5),perindopril group(39+2.18),atorvastatin calcium combine perindopril group(39.3+1.98),expect for normal control group,there were no significance statistic compare between any two group.1.2 The percent of myocardial infarction areas(ICS/LV%),Myocardial infarction areas in the reperfusion models were more higher than in normal control model, placebo group(50.0+2.00) was higher than that in atorvastatin calcium group (29.67+ 2.08),perindopril group (35.33 +1.53),atorvastatin calcium combine perindopril group (29+ 2.00),atorvastatin calcium group was less than perindopril group (p<0.05),atorvastatin calcium group was higher than atorvastatin calcium combine perindopril group(P>0.05),perindopril group was more than atorvastatin calcium combine perindopril group(P<0.05).2. The result of RT-PCR methods to evaluate the expression of MMP-2mRNA,MMP-9mRNA,TIMP-2mRNA on myocardium in rabbits.2.1 Under normal condiction,the expression of MMP-2 mRNA,MMP-9 mRNA,TIMP-2 on myocardial in rabbits was thinness. After reperfused to rabbits myocardial,the expression of MMP-2 mRNA,MMP-9 mRNA was increasing,the expression of TIMP-2 mRNA on myocardial in rabbits was inhibited.2.2 Among atorvastatin calcium group,perindopril group,atorvastatin calcium combine perindopril group,the expression of MMP-2,MMP-9 was obviously inhibited compared to placebo group (P<0.05), atorvas- tatin calcium group was lower than perindopril group(P>0.05),higher than atorvastatin calcium combine perindopril group,perindopril group was higher than atorvastatin calcium combine perindopril group (P<0.05).the expression of TIMP-2 was obviously up-regulate compared to placebo group(P value,0.142,0.047,0.025),atorvastatin calcium group was higher than perindopril group(P>0.05),lower than atorvastatin calcium combine perindopril group(P>0.05),perindopril group was lower than atorvastatin calcium combine perindopril group(P>0.05).3. The result of immunohistochemistry staining method to evaluate the expression of MMP-2,MMP-9,TIMP-2 on myocardial in rabbits.(Mean density was used to describe the level of the MMP-2,MMP-9,TIMP-2 expression)3.1 Under normal condiction,the mean optical density of MMP-2,TIMP-2 on myocardial cytoplasm,MMP-9 on myocardial interstitial in rabbits was thinness. After reperfused to rabbits myocardial,the mean optical density value of MMP-2,MMP-9 was increasing in myocardial cytoplasm in rabbits,the mean density of TIMP-2 was descreased relatively.3.2 Among atorvastatin calcium group,perindopril group,atorvastatin calcium combine perindopril group,the mean optical density value of MMP-2,MMP-9 was obviously lower compared to placebo group(P<0.05),atorvastatin calcium group was lower than perindopril group(P>0.05),higher than atorvastatin calcium combine perindopril group(P>0.05),perindopril group was higher than atorvastatin calcium combine perindopril group.the mean optical density value of TIMP-2 was obviously increasing compared to placebo group,atorvastatin calcium group was higher than perindopril group(P >0.05),lower than atorvastatin calcium combine perindopril group(P>0.05),perindopril group was lower than atorvastatin calcium combine perindopril group(P>0.05).Conclusion1. Under normal condition , MMP-2,MMP-9,TIMP-2 were found expression in normal myocardial tissure,but that the expression level was very thinness.During myocardial reperfusion, MMP-2,MMP-9 were actived,the expression level was increasing. but TIMP-2 was inhibited.2. Short-term preconditioning with atorvastatin calcium and perindopril,the expression of MMP-2,MMP-9 on myocardial in rabbits were evidently inhibited during reperfusion,at the same time,the expression of TIMP-2 was up-regulate during reperfusion.3. Short-term preconditioning with atorvastatin calcium and perindopril,which can reduce myocardial infarction areas,and the atorvastatin calcium was more stronger. Atorvastatin calcium combine perindopril was more heavily inhibit the expression of MMP-2,MMP-9 on myocardial in rabitts during reperfusion,up-regulate the expression of TIMP-2,and apparently decreasing the myocardial infarction areas.4. High-does atorvastation calcium precondition can reduce myocardial reperfusion injury tmaybe involve to mechanism of coronary inhibit MMPs over expression and up regulate TIMPs, inhibit the ignites of ventricular reconstruction, rescue left contractile function,and this action of atorvastation calcium may be have an importment application in ACEI improve ventricular reconstruction,rescue left contractile function in long-term post myocardial infarction.