Objective     To study on anti-inflammatory action of simvastatin in rats with chronic obstructive pulmonary disease (COPD) and its mechanism.

  Methods     A total of 50 male SD rats were given 7 d adaptive feeding, and 10 rats were randomly selected and taken as blank control group, and the remaining 40 rats were used to establish COPD model. After successful modeling, they were randomly divided into four groupsthe model group, low-dose group, middle-dose group and high-dose group simvastatin, with 10 rats in each group. The bronchoalveolar lavage fluid of rats was collected, and the levels of inflammatory factors were detected. The expression of retinoic acid related orphan receptor ROR-γt mRNA was measured, and the pulmonary function was evaluated.

  Results     The levels of pulmonary function indexes of rats in blank control group were the highest, and the rank of the rest four groups from high to low was as follows: high-dose group, middle-dose group, low-dose group and model group. There were no statistically significant differences in the levels of inflammatory factors and the relative expression of ROR-γt mRNA between the low-dose and medium-dose groups (P>0.05). There were statistically significant differences in the levels of inflammatory factors and the relative expression of ROR-γt mRNA among other groups (P < 0.05).

  Conclusion     Simvastatin has an ideal anti-inflammatory effect for COPD rats, which may be related to the inhibition of ROR-γt expression by drugs, and the mechanism is that pulmonary function of rats can be improved by inhibiting inflammation.