QUALITATIVE AND QUANTITATIVE SEX-RELATED DIFFERENCES IN GLUTATHIONE S-TRANSFERASES OF MOUSE KIDNEY

Since some of the previous studies have indicated significant sex-rela ted differences in glutathione S-transferases (GST) of rodent tissues, we have characterized and compared GST isozymes of male and female mo use kidney. GST isozymes with pI values 9.9, (alpha class), 8.8 (pi cl ass), 7.2 (mu class) and 5.7 (a subclass within the alpha-class) were present in both male and female kidney. Female kidney had relatively h igher amounts of proteins corresponding to GST 9.9 and GST 8.8, while other two isozymes were expressed in comparable amounts in male and fe male kidney. Specific activity of the alpha-class GST towards 1-chloro -2,4-dinitrobenzene from female kidney was consistently found to be ab out 2 fold higher than that of the corresponding isozyme from male kid ney. In contrast, the specific activity of the pi-class isozyme from m ale kidney was about 1.4 fold higher as compared to that from female k idney. The pi-class isozyme from male kidney was found to be comparati vely more heat stable than the enzyme from female kidney. Sex-related differences were also observed in the kinetics of inhibition of the pi -class GST by hematin.