Toxic effects of an anionic detergent on the gills of rainbow trout

The changes that occur in the gill tissue of rainbow trout exposed to 100 mg l⁻¹ sodium lauryl sulphate are typical of an acute inflammatory reaction and are in general similar to the changes induced in gills by other toxic agents. The gill epithelium lifts away from the underlying tissue, and lymphocytes and granulocytes invade the subepithelial spaces. Large numbers of epithelial cells die and are sloughed off, but puncture of the epithelium does not occur. Detailed changes at the cellular level, mostly related to cell death, distinguish SLS-induced damage from that caused by zinc sulphate. Epithelial lifting may be a consequence of a decrease in gill surface area imposed by the need to maintain osmotic stability while sustaining the progressive loss of epithelial cells caused by pollutant action.