Histopathological Changes of the Gills Induced by a Group of Amphoteric Surfactants in the Common Carp

抄録

The histopathological effects of a homologous series of amphoteric surfactants, N-alkyl (C₈-C₁₈)-N, N-dimethyl-3-ammonio-1-propane sulfonate, on the gills of common carp Cyprinus carpio were examined by light microscopy. Fish were exposed to the lethal concentration (96-h LC₅₀) of each surfactant for 96 h. The gills exposed to C₈ showed slight hypertrophy of epithelialcells and epithelial lifting of the secondary lamellae. Marked epithelial lifting was observed after the exposure to C₁₀. In the groups exposed to C₁₂, C₁₄, and C₁₆, hyperplasia between thesecondary lamellae occurred to such an extent that it led to lamellar fusion. In the gillsexposed to C₁₈, hyperplasia was more advanced and revealed fusion of the primarylamellae. These findings suggest that the extent of gill damage induced by this homologous series of amphoteric surfactants progressively deteriorated withthe increase in the number of carbon atoms in the alkyl chain.