Superoxide dismutase and glutathione peroxidase activities in rat pineal gland.

Activities of the antioxidant enzymes superoxide dismutase (E.C.1.15.1.1) and glutathione peroxidase (E.C.1.11.1.9) were measured in the pineal gland of adult rats. For comparative purpose superoxide dismutase was also measured in the anterior hypothalamic area (suprachiasmatic region) and the liver and glutathione peroxidase in the liver. The mean activities obtained for superoxide dismutase were: pineal (103.13 +/- 4.70 N.U.), anterior hypothalamus (132.88 +/- 4.73 N.U.), liver (253.91 +/- 0.10 N.U.) and, for glutathione peroxidase were: pineal (0.027 +/- 0.005 I.U.) and liver (0.103 +/- 0.031 I.U.). It was shown for the first time that superoxide dismutase and glutathione peroxidase are present in pineal gland being part of its antioxidant defense system.