Pretreatment With Simvastatin Attenuates Myocardial Damage Induced By Isoproterenol In The Rats

Objective: To investigate the effects of pretreatment with simvastatin on the myocardial damage induced by isoproterenol in experiment rats. Methods: Rats were randomly divided into simvastatin pretreatment group (SP group), myocardial damage group (MD group) and control group(C group). Each group contained 12 rats. The SP group was treated with simvastatin (20mg.kg-1.d-1) for 14 days before myocardial damage; the other two were treated with saline vehicle. On the 15th day, the SP group and MD group were injected with isoprenaline (ISO, 5mg.kg-1) interaperitoneally to develop acute myocardial damage model. Blood was withdraw and the ratio and number of CD34+ mononuclear cell and the serum level of troponin I (TnI), NOx, total cholesterol and triglyceride were determined at 24h, 48h after administration of ISO. At the same time, the hearts were harvested for histopathological examination. Results: 1.The serum levels of total cholesterol and triglycerid were no statistically significant differences between groups (p>0.05). 2.The serum level of TnI was significantly elevated in the SP group (P <0.05 vs C group) and the MD group (P <0.01 vs C group) compared with the C group at 24h after administration of ISO. However, 48h after administration of ISO, the serum levels of TnI were no significantly different between groups. 3.Compared with the other two groups, the SP group significantly elevated the serum level of NOx (P<0.01). The serum NOx level of MD group was significantly lower than that of C group (p<0.05 after 24h; p<0.01 after 48h). 4. The numbers of mononuclear cell in peripheral blood were no significantly different between groups. The ratio and the number of CD34+ mononuclear cell were higher than the other two groups (p<0.01). 5. 24h after administration of ISO, myocardial damage zones scattered in the pallium of the MD group, there were a large amount of inflammatory cells infiltration around the damage zones and majority of them were neutrophils. The damage in the SP group was milder, majority of infiltrative cells were monocytoid; 48h after administration of ISO, damage zones expanded greatly in MD group, while that of the SP group increased just mildly. CONCLUSION: 1.Simvastain pretreatment could attenuate myocardial damage induced by isoproterenol in the rats. 2.Pretreatment with simvastatin could elevate the serum level of NOx. 3. Pretreatment with simvastatin could increase the ratio and the number of CD34+ cell in peripheral blood mononuclear cell.