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

Abstract

Cu,Zn-superoxide dismutase is an endogenous scavanger of superoxide radicals (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 arterial wall of atherosclerotic subjects. The aim of this study was to investigate the Cu,Zn-superoxide dismutase activity in erythrocytes and ceruloplasmin activity in serum, and to measure serum concentrations of copper, zinc, and malonyldialdehyde in patients with moderate and critical chronic ischemia of the lower limbs. A group of 26 patients with chronic arterial occlusion 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 oxidase activity was determined with o-dianisidine as a substrate. Copper and zinc concentrations in serum were determined by atomic absorption spectrometry. 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 micromol/l, respectively) compared with moderate ischemia (139.1+/-34.9 U/l and 18.5+/-2.0 micromol/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 critical ischemia. There was a negative correlation for Cu,Zn-superoxide dismutase and ceruloplasmin (r=-0.60, P</=0.05) in critical ischemia.