The influence of environmental contaminants on lysosomal activity in the digestive cells of mussels (Mytilus galloprovincialis) from the Venice Lagoon

Lysosomes are subcellular organelles bounded by a semipermeable lipoprotein membrane that contain a battery of hydrolytic enzymes that are collectivel y capable of degrading all classes of indogenous and exogenous macromolecul es. Lysosomes accumulate a diverse range of chemical contaminants which can lead to membrane damage resulting in leakage of their contents into the cy tosol and damage to cells. Total lysosomal activity for two acid hydrolases , N-acetyl-beta-D-hexosaminidase and beta-glucuronidase, with different sub strate specificities was determined histochemically in digestive gland sect ions of mussels, Mytilus galloprovincialis from a series of sites in the Ve nice Lagoon and the Adriatic Sea and correlated, using multi-stepwise regre ssion analysis, with tissue contaminant burdens in order to explore causali ty. The results indicated that whilst activity of N-acetyl-beta-D-hexosamin idase correlated with body burdens of mercury, 8-glucuronidase, by contrast , correlated with DDT, Arochlor 1254 and eight PCB congeners in combination with iron or zinc. (C) 2000 Elsevier Science B.V. All rights reserved.