Glutathione S-transferase in human organs

Glutathione S-transferase (GSH-T) distribution has been investigated in human tissues. The relative contribution of each species to total enzyme activity of the various tissues has been compared. 'Cationic' (pI>7.5) 'neutral' (pI 6-6.5) and 'anionic' (pI<5.4) species of GSH-T were separated by isoelectric focusing. 'Cationic' GSH-Ts (ligandin) quantitated by radioimmunoassay were present in all tissues studied. Highest concentrations were in liver, kidney, duodenum, testis and adrenal. 'Neutral' and 'anionic' GSH-Ts were not present in every tissue or in every specimen of some tissues studied. Marked inter-organ and inter-individual variation in the relative concentration of the 3 GSH-T species may explain individual and organ susceptibility to drugs and toxins and underlines the need for future studies to examine individual enzymes rather than total activity.