Superoxide dismutase from bovine erythrocytes has been used in a study to assess a kinetic model of radiation-induced inactivation of superoxide dismutase in nitrous oxide-saturated solutions. 1 Superoxide dismutase from bovine erythrocytes has also been used in a study to investigate the possible participation of superoxide anion in the intestinal tryptophan 2,3-dioxygenase reaction. It also catalyzes the dismutation of superoxide radicals to hydrogen peroxide and molecular oxygen. Plays a critical role in the defense of cells against the toxic effects of oxygen radicals. Competes with nitric oxide (NO) for superoxide anion (which reacts with NO to form peroxynitrite), thereby SOD promotes the activity of NO.3 SOD has also been shown to suppress apoptosis in cultured rat ovarian follicles, neural cell lines, and transgenic mice.