Superoxide Dismutase Levels in Leukemias

Superoxide dismutase is antioxidant enzyme responsible for the quenching of superoxide radicals which are released during the chemical reactions of the various metabolic pathways. It is a non-heme protein. Different iso-enzymes of superoxide dismutase are described. The mitochondrial enzyme is manganese dependent, cytoplasmic enzyme is copper-zinc dependent. These enzymes are evenly and ubiquitously distributed among aerobic organisms and tissues but are found in appreciable quantities only inside the cell. Superoxide dismutase work in conjugation with two enzymes that remove H O in human cells: Catalase, and glutathione peroxidase. The enzyme levels of superoxide dismutase are altered to considerable extent in various diseased states exhibiting either elevation or depletion in their activity, this phenomenon was found to be more evident in leukemias. We have determined the superoxide dismutase activity in the red blood cells of leukemic patients and these levels were significantly low as compared to control. In respect to sex, the mean superoxide dismutase levels in males (3.268 ± 0.305) were found to more than that in females (3.165 ± 0.337) however, we found significant difference only in patients with chronic myeloid leukemia. Whereas in respect to age, the mean superoxide dismutase levels were found to elevated (in < 10 years value was 2.845 ± 0.266 whereas in age >51 years value was 3.442 ± 0.247) indicating the extent of the free radicals might have stimulated the production of the antioxidant. We observed highly significant (p<0.001) superoxide dismutase levels in acute leukemias with respect to age. Our results suggest that oxidative stress in leukemia patients causes the deficiency in antioxidant enzyme superoxide dismutase, which arise as a result of enormous production of reactive oxygen species in the system. 2 2