Effect Of Simvastatin On The Expression Of IL-6 And MMP-9 In Chronic Obstructive Pulmonary Disease Rats Model And The Mechanism

Objective Studying the influence of simvastatin on IL-6 expression in serum and MMP-9 expression in lung tissue in chronic obstructive pulmonary disease rats models, to explore the influence and mechanism of simvastatin in chronic obstructive pulmonary disease.Methods Wistar rats (n=30) were randomly divided into three groups, normal control group, COPD group and simvastatin treated group, each group was ten. The COPD rats models were established by using intratracheal injection of lipopolysaccharide and exposing to cigarette smoke. The COPD model group were intratracheal instillation of lipopolysaccharide (LPS) 200μg / 200μl at 1,15 day, No. 2 ~ 14d, 16 ~ 42d were exposed to cigarette smoke for 2h per day. Simvastatin treated group were giving simvastatin 5mg/kg before exposed to cigarette smoke from the eighth day. Rat lung tissue pathological changes were observed. We detected the expression of IL-6 in serum and MMP-9 in lung tissue using radioimmunoassay and immunohistochemistry respectively.Results Pathological changes in rats generally consistent with the human characteristics of COPD. The expression of IL-6 in COPD group were significantly increased compared with normal control group (P<0.05); in simvastatin treated group they remarkably decreased compared to COPD group (P<0.05). The expression of MMP-9 in COPD group were significantly increased compared with normal control group (P<0.05); in simvastatin treated group they remarkably decreased compared to COPD group (P<0.05).Conclusion (1) By using intratracheal injection of lipopolysaccharide and exposing to cigarette smoke can be successfully established the COPD rats models, and pathological changes in rats models generally consistent with the human characteristics of COPD. (2) The expression of IL-6 and MMP-9 in COPD group were significantly increased compared with normal control group, it confirmed that IL-6 and MMP-9 have an important role in the formation of COPD. (3) Simvastatin may reduce the expression of IL-6 and MMP-9 to inhibit the chronic inflammation of the COPD and slow down the development of COPD, which play a therapeutic role.