LAUSR

We determined the concentration of glutathione (GSH) and the activity of glutathione S-transferase (GST) in the gills and hepatopancreas of the freshwater pearl mussel Margaritifera margaritifera L. It was found that the concentration of GSH in the gills decreases with a decrease in temperature, which indicates that metabolic processes in these ectothermic animals are decelerated. It was also found that changes in the concentration of GSH and in the activity of GST do not depend on age; thus, these biochemical markers can be used as bioindicators regardless of age. No substrate-specific activity of GST was observed, which means that freshwater pearl mussels have limited ability to metabolize compounds with different chemical structures.