TOXIC ACTION OF SEVERAL LETHAL CONCENTRATIONS OF AN ANIONIC DETERGENT ON GILLS OF BROWN TROUT (SALMO-TRUTTA-L)

The pathological effects of 10 lethal concentrations of the anionic detergent, sodium lauryl sulfate, on the gills of S. trutta were studied by light microscopy and EM. At concentrations to 120 mg/l (medium survival times > 1 h), epithelial cell death is associated with lysosome formation. Acute inflammation of the gill tissue, extensive detachment of the epithelium and, except at the lowest concentrations, collapse of the pillar cell system occur. At concentrations above 120 mg/l (medium survival times < 1 h) very rapid lysis of cells results in the complete disruption of cellular and tissue structure. Changes in the gross structure of the gills are explainable in terms of the rate and nature of toxic action at the cellular level. Review of the biomedical literature suggests the observed effects of sodium lauryl sulfate on gill cells correspond to the 2 mechanisms by which detergents cause death in isolated cells. These are autolysis, i.e., lysis by the action of the cell''s own enzymes, induced by an initial lesion in the cell membrane whose precise nature is not known, and rapid lysis by the direct action of the detergent on the cell constituents.