Antioxidant levels from different Antarctic fish caught around South Georgia Island and Shag Rocks
Ansaldo Martin; Luquet Carlos, M.; Evelson Pablo, A.; Polo Jose, M.; Llesuy Susana
Polar Biology 23(3): 160-165
The oxidative stress affecting the metabolic adaptive strategy of Antarctic fish evolved from several million years in an isolated environment with a very low and constant temperature and high oxygen concentration. Activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), vitamin E levels and total antioxidant capacity (TRAP) were measured in liver, gill, heart and muscle homogenates of red-blooded (Nototheniidae) and white-blooded (Channichthyidae) Antarctic fish. SOD activity was also measured in blood samples. The H (sub 2) O (sub 2) produced seems to be preferentially eliminated by diffusion. Blood SOD was about fivefold higher in the group possessing erythrocytes and thus a much higher oxygen-carrying capacity. CAT activity was always higher in nototheniids except in muscle. Vitamin E did not show clear differences between families except for the pattern observed in muscle. The higher content of vitamin E in this tissue shown in channichthyids is related to the higher volume density of mitochondria reported for this group, since vitamin E is responsible for preventing membrane lipid peroxidation.(modified journ. abstr.).