·AIM:To observe the effect of tetramethylpyrazine(TMP)on superoxide dismutase(SOD)、malonaldehyde(MDA)and catalase(CAT)of isolated rat lens in vitro.·METHODS:The rats were randomly divided into 7 groups and the lens in each group were isolated and cultured with RPMI-1640 culture fluid and different concentrations of TMP solution(0,0.125,0.25,0.5,1,2 and 4g/L).After cultured for 24 hours,the transparency of the lens was observed with wake eye and homogenated.The enzyme activation levels of SOD、CAT and the contents of MDA were measured by photometry respectively.·RESULTS:Compared with normal group,0.25,0.5,1 and 2g/L TMP could obviously increase the activity of SOD,P<0.01,P<0.01,P<0.01 and P<0.05 respectively,while 0.125 and 4g/L TMP had no significance effect.Compared with normal group,0.5g/L TMP could improve the activity of CAT,P<0.01 while other concentrations of TMP had no significance effect.Compared with normal group,0.125,0.25,0.5,1 and 2g/L TMP could obviously decrease the content of MDA,P<0.01,while 4g/L TMP had no significance effect.·CONCLUSION:TMP could increase enzyme activation of SOD and CAT,and decrease contents of MDA in isolated lens of rats.·