Influence and mechanism of simvastatin on cell apoptosis in lung tissue of chronic obstructive pulmonary disease rat model

Objective To discuss the effect and mechanism of simvastatin on cell apoptosis in chronic obstructive pulmonary disease(COPD).Methods 30 rats were randomly divided into three groups:the normal group,the control group and the treatment group.The control and treatment groups were established as COPD models,2 weeks later after beginning,the treatment group was treated with simvastatin daily for 6 weeks,and to execute all rats on weekend 8.Lung tissue sections stained by hematoxylin and eosin(HE) were observed.Lung tissues cell apoptosis was detected with TUNEL method,and count for apoptosis index(AI).The mRNA expression of eNOS,iNOS and Caspase-3 were measured by RT-PCR.Results In normal group,the AI of alveolar epithelia were 6.21%±1.28%,the AI of airway epithelia were 3.55%±0.87%;in control group,they were 31.41%±2.67%,17.86%±2.7% respectively,while in treatment group,they were 20.98%±3.00%,10.20%±1.52%.Contrast to normal group,the control group and treatment group airway epithelium and alveolar epithelial cell can be found more apoptosis(P0.05),there was more apoptosis cell in control than treatment group(P0.05).Compared with the normal group,the mRNA expression of eNOS was decrease(P0.05)in the control and treatment group,and iNOS,Caspase-3 increase(all P0.05),the mRNA expression of eNOS was increase(P0.05) and iNOS、Caspase-3 decrease(P0.05) in the treatment group compared with the control group.The mRNA expression of Caspase-3 in the lung correlated positively with the iNOS(r values were 0.94,0.89,0.91 respectively),and negatively with the eNOS(r values were-0.88,-0.65,-0.92 respevtively).Conclusion Simvastatin could inhibit cell apoptosis of COPD rats,the reason might be it could increase the mRNA expression of eNOS,and decrease mRNA expression of iNOS,Caspase-3.