Histopathological observations on organs from rabbits injected with the skin toxin of the Arabian Gulf catfish (Arius bilineatus, Valenciennes)

Toxicity of soluble protein extracts (skin toxin) from epidermal skin secretions of the catfish, Arius bilineatus (previously identified as Arius thalassinus), was examined in rabbits. Intravenous injections containing doses as low as 2 mg protein/kg body weight caused mortality in most animals tested. Histopathological examination of lung, heart, liver and kidney tissues of rabbits injected with skin toxin indicated that the lungs and livers of treated animals were adversely affected, while heart and kidney tissues appeared to be normal. Lethality of skin toxin was prevented by pretreatment of the rabbits with indomethacin. Histopathological examination of lung and liver tissues of indomethacin pretreated animals showed a significant reduction in the damage observed after injection of skin toxin.