Objective To investigate the effect of γ-glutamylcysteine synthetase (γ-GCS),in the kidney fibrosis of MRL/lpr lupus mice.Methods The expression of connective tissue growth factor(CTGF)and γ-GCS in the kidney tissue of MRL/lpr lupus mice and control mice were detected by reverse transcriptase PCR (RT-PCR)and immunohistochemistry.The relationship between CTGF and γ-GCS was analyzed.Results The transcription and expression of CTGF in the kidney tissue of MRL/lpr lupus mice was significantly higher as compared with that of the control mice(CTGF mRNA:1.052±0.004 vs 0.402±0.009,P<0.01;CTGF protein:3.364±0.460 vs 1.206±0.271,P<0.01);whereas the expression of γ-GCS mRNA was decreased in MRL/lpr lupus mice(0.952±0.011 vs 1.145±0.066,P<0.01).Pearson's regression analysis showed that there was a negative correlation between CTGF and γ-GCS(r=-0.902,P<0.01).Conclusion The decreased expression of γ-GCS in the kidney of MRL/lpr lupus mice may compromise the ability of antioxidative stress,and there is a negative correlation between γ-GCS and CTGF.This suggests that the perturbation of γ-GCS may contribute to the progress of kidney fibrosis.