The activities of the enzymes superoxide dismutase (EC.1.15.1.1), and catalase (EC.1.11.1.6) in purified extracts of whole Ascaris suum adult males and females, and also in several analogous tissues of each sex, were studied. 2. No catalase activity was found in any of the extracts. 3. Considerable superoxide dismutase activity was detected in both sexes and the levels of this activity showed sexual differences in the values found in different tissue locations. 4. The sexual organs of both males and females showed the highest SOD activity of all the tissues examined. 5. Polyacrylamide gel electrophoresis pattern analysis confirmed that the female tissues had more SOD enzyme components than the corresponding tissues in the male.
