The Intervention Study Of Atorvsatin On NADPH Oxidase In Rat Aortic Smooth Muscle Tissue After Myocardial Infarction

Objective:To explore the changes of NADPH oxidese and the intervention study on NADPH oxidase with atorvastatin in rat aortic smooth muscle tissue after myocardial infarction.Methods:Using male SD (Sprague-Dawley) rats, MI group was made by ligation of anterior descending coronary artery, the sham group underwent the same procedure without coronary artery ligation. The MI rats were assigned randomly to intragastrically receive atorvastatin (10mg/kg/day) or saline respectively on the second day after operation for 5 weeks. On the sixth week after the operation,the rats were killed and the rat aortic vascular smooth tissue were taken. The concentration of O2- was measured with WST-1 method and the expression levels of Nox1 mRNA and Nox4 mRNA were detected with RT-PCR, and the correlations between the concentration of O2- and the expression levels of Nox1 mRNA and Nox4 mRNA were respectively calculated.Results: 1.The concentration of O2- in the MI group [(53300±6514)RLU/mg] increased significantly compared to the sham group [(30800±2412)RLU/mg](P<0.01). The concentration of O2- in the MI intervention group [(32900±4214)RLU/mg] decreased significantly compared to the MI group (P<0.05). There was no significant difference beween the MI intervention group and the sham group(P=0.36).2.The expression level of Nox1 mRNA in the MI group increased significantly compared to the sham group [(0.68±0.05) vs (0.44±0.06),P<0.01]. The expression level of the Nox1 mRNA in the MI intervention group decreased significantly compared to the MI group [(0.46±0.05) vs (0.68±0.05), P<0.05]. There was no significant difference between the MI intervention group and the sham group (P=0.54), The expression level of Nox4 mRNA in the MI group increased significantly compared to the sham group [(0.67±0.06) vs (0.46±0.08), P<0.01]. The expression level of Nox4 mRNA in the MI intervention group decreased significantly compared to the MI group [(0.67±0.06) vs (0.48±0.07), P<0.05]. There was no significant difference between the MI intervention group and the sham group (P=0.48).3.The concentration of O2- positively correlated to the expression levels of Nox1 mRNA and Nox4 mRNA respectively (R=0.53, P<0.05;R=0.56, P<0.05 respectively).Conclusions: 1.The concentration of O2-, the expression levels of Nox1 mRNA and Nox4 mRNA in the MI group increase significantly. There are positive correlations between the concentration of O2- and the expression levels of Nox1 mRNA and Nox4 mRNA.These indicate that the NADPH oxidase system is actived in rat aortic smooth muscle after myocardial infarction.2.The atorvsatin decreases the production of O2- by inhibiting the expression level of Nox1 mRNA and Nox4 mRNA. This suggests that atorvsatin could significantly attenuate the level of oxidase stress in rat aortic smooth muscle after myocardial infarction.