Activities of copper,zinc-superoxide dismutase in erythrocytes and ceruloplasmin in serum in chronic ischemia of lower limbs

Cu,Zn-superoxide dismutase is an endogenous scavanger of superoxide radical s (O-2(-)) which also induce the synthesis of this enzyme. Ceruloplasmin is an antioxidant and acute-phase reactant. Changes in the synthesis of both enzymes are related to the metabolism of copper and zinc. Concentrations of copper and zinc were previously found to be increased in the serum and art erial wall of atherosclerotic subjects. The aim of this study was to invest igate the Cu,Zn-superoxide dismutase activity in erythrocytes and cerulopla smin activity in serum, and to measure serum concentrations of copper, zinc , and malonyldialdehyde in patients with moderate and critical chronic isch emia of the lower limbs. A group of 26 patients with chronic arterial occlu sion of the lower limbs was divided into two groups depending on the degree of ischemia: moderate and critical. Cu,Zn-superoxide dismutase activity in erythrocytes was measured using the RANSOD kit, the serum ceruloplasmin ox idase activity was determined with o-dianisidine as a substrate. Copper and zinc concentrations in serum were determined by atomic absorption spectrom etry. There was an increase in the ceruloplasmin activity and serum copper concentration in critical ischemia (194.4+/-51.94 U/l and 23.5+/-4.2 mu mol /l, respectively) compared with moderate ischemia (139.1+/-34.9 U/l and 18. 5+/-2.0 mu mol/l, respectively). The Cu,Zn-superoxide dismutase activity in erythrocytes was higher in moderate ischemia (2,657+/-1,564 U/g hemoglobin ) than in controls (1,205+/-353 U/g hemoglobin), but not different from cri tical ischemia. There was a negative correlation for Cu,Zn-su-peroxide dism utase and ceruloplasmin (r=-0.60, P less than or equal to 0.05) in critical ischemia.