The effect of an anionic detergent on complex carbohydrates and enzyme activities in the epidermis of the catfish Heteropneustes fossilis (Bloch)

Summary The histochemistry of various oxidative enzymes and complex carbohydrates in the epidermis of the catfishHeteropneustes fossilis was investigated after exposure to sublethal concentrations of the detergent sodium alkulbenzenesulphonate.It was found that the detergent treatment was accompanied by a marked increase in the number of mucous cells which produce histochemically detectable amounts of acidic glycoproteins with a shift towards the production ofO-acetylated sialic acids. The activities of mitochondrial enzymes were lost in the superficial cell layers. In contrast the activities of glucose-6-phosphate and lactate dehydrogenase increased considerably. The rise in glucose-6-phosphate dehydrogenase was correlated with the metabolic requirements for the enhanced production of mucus under stress.The changes in both enzyme activities and in the chemical composition of mucus may provide a suitable experimental model for histochemical investigations of the effect of stress induced by pollulants on aquatic organisms.