Objective:To discuss the effect of azathioprine(AZA)on ferroptosis in spermatocytes of the mice induced by reduced glutathione(GSH)peroxidase 4 inhibitor RSL3,and to clarify the potential mechanism.Methods:The spermatogonia GC-2 cells of the mice were randomly divided into control group(no treatment),RSL3 group(treated with 10 nmol·L-1 RSL3 for 24 h),RSL3+ferroptosis inhibitor(Ferrostatin-1,Fer-1)group(treated with 10 nmol·L-1 RSL3 for 24 h+2 μmol·L-1 Fer-1 for 12 h),RSL3+low dose of AZA group(treated with 10 nmol·L-1 RSL3 for 24 h+5 μmol·L-1 AZA for 12 h),RSL3+medium dose of AZA group(treated with 10 nmol·L-1 RSL3 for 24 h+10 μmol·L-1 AZA for 12 h),and RSL3+high dose of AZA group(treated with 10 nmol L-1 RSL3 for 24 h+20 μmol·L-1 AZA for 12 h).The MTT method was used to detect the activities of the GC-2 cells in various groups after treated with different concentrations of AZA and RSL3;the GSH and GSSG levels in the GC-2 cells were detected by GSH and oxidized glutathione(GSSG)detection kits;the malondialdehyde(MDA)levels in the GC-2 cells in various groups were detected by MDA detection kit;Western blotting method was used to detect the expression levels of long-chain acyl-CoA synthetase 4(ACSL4),heme oxygenase-1(HO-1),and glutathione peroxidase 4(GPX4)proteins in the cells in various groups;immunofluorescence staining was used to detect the expressions of ACSL4 protein in the cells in various groups.Results:Compared with control group,the differences in activities of the GC-2 cells in 5,10,and 20 μmol·L-1 AZA groups had no significant differences(P＞0.05),while the activities of the GC-2 cells in 30 and 40 μmol·L-1 AZA groups were significantly decreased(P＜0.01);therefore,the AZA concentration was selected to be within 20 μmol·L-1.Compared with control group,the differences of the activities of the GC-2 cells in 1,5,and 10 nmol·L-1 RSL3 groups had no significant differences(P＞0.05),while the activities of the GC-2 cells in 50,100,500,and 1 000 nmol·L-1 RSL3 groups were significantly decreased(P＜0.05 or P＜0.01);therefore,the RSL3 concentration was set to be within 10 nmol·L-1.The GSH and MDA detection kits results showed that compared with control group,the levels of GSSG and MDA in the GC-2 cells in RSL3 group were significantly increased(P＜0.05),while the GSH levels were significantly decreased(P＜0.05);compared with RSL3 group,the levels of GSSG and MDA in the GC-2 cells in RSL3+Fer-1 group and RSL3+AZA group were significantly decreased(P＜0.01),while the GSH levels were significantly increased(P＜0.01).The Western blotting results showed that compared with control group,the expression levels of ACSL4 and HO-1 proteins in the GC-2 cells in RSL3 group were significantly increased(P＜0.05),while the expression level of GPX4 protein was significantly decreased(P＜0.01);compared with RSL3 group,the expression levels of GPX4 protein in the GC-2 cells in RSL3+Fer-1 group and RSL3+AZA group were significantly increased(P＜0.05),while the expression levels of ACSL4 and HO-1 proteins were significantly decreased(P＜0.01).The immunofluorescence staining results showed that compared with control group,the expression amount of ACSL4 protein in the GC-2 cells in RSL3 group was significantly increased,and compared with RSL3 group,the expression amounts of ACSL4 protein in the cells in RSL3+Fer-1 group and RSL3+AZA group were significantly decreased.Conclusion:AZA can alleviate the ferroptosis-induced by RSL3 in spermatocytes of the mice.