Aim: To investigate the effects of MnCl2 on testosterone biosynthesis in Leydig cell from the SD rat testis.Methods:Ⅰ:Based on the primary Leydig cell culture model, MnCl2 exposure groups were given 0 μmol/L,1.0 μmol/L,2.5 μmol/L,5.0 μmol/L,10.0 μmol/L,25.0 μmol/L,50.0 μmol/L and 100.0 μmol/L MnCl2,respectively.Trypan blue dye exclusion method was used to observe the cell survival.Ⅱ:The groups were allocated as above, the testosterone level was measured by RIA when being stimulated by HCG or without HCG.Res...