Dietary superoxide dismutase does not affect tissue levels.

The effects of dietary supplementation of superoxide dismutase on tissue superoxide dismutase levels were examined in mice. Mice were divided into two groups; the control received a complete purified diet, and the supplemented group received the same diet containing 0.004% superoxide dismutase. There were no differences in the activity of CuZn superoxide dismutase or Mn superoxide dismutase in intestine, liver, kidney, or blood. These data show that oral supplementation of superoxide dismutase does not affect tissue superoxide dismutase activity.