AGE-RELATED DIFFERENCES IN GLUTATHIONE METABOLISM IN MUSSEL TISSUES (MYTILUS-EDULIS L)

Previous data indicate that in the digestive gland of marine mussels ( Mytilus edulis L.) aging process is accompanied by increased oxidative stress conditions and reduction in the antioxidant defense systems an d, among these, in the tissue levels of glutathione (GSH). Data are pr esented here on the tissue glutathione content and on the activity of the main enzymes involved in GSH metabolism (gamma-glutamyl-cysteine s ynthetase, gamma-glutamyl transpeptidase, GSSG reductase, GSH transfer ase) in the gills and digestive gland of mussels of three different ag e groups. The results indicate that the glutathione content was progre ssively decreased in both tissues of aging mussels. Similarly, aging s eems to affect the activity of GSH related enzymes and, in particular, the activity of gamma-glutamyl cysteine synthetase, the enzyme that r epresents the rate limiting step in GSH biosynthesis. These data indic ate that, in aging mussels, the increased susceptibility to oxidative stress is partly related to alteration of glutathione metabolism. The results are discussed in the light of the current hypotheses on the ag ing process. Copyright (C) 1997 Elsevier Science Inc.