Bovine ocular squamous cell carcinoma: superoxide dismutase and catalase levels

Considerable evidence exists for the production of free radicals in the eye region after exposure to ultraviolet light. Failure to remove these radicals adequately may be important in the predisposition of Hereford cattle to ocular carcinoma. The levels of two enzymes, superoxide dismutase and catalase, involved in the removal of superoxide anion and hydrogen peroxide, were compared in Hereford cattle predisposed to ocular carcinoma and a resistant breed, Droughtmaster cattle. The results demonstrate comparable levels of superoxide dismutase in the two breeds in both eye tissue and erythrocytes. Catalase levels also were the same in both breeds. Increased incidence of ocular carcinoma in Herefords does not appear to be due to a deficiency in either superoxide dismutase or catalase.