Oxidase activity of ceruloplasmin and concentrations of copper and zinc inserum in chronic arterial occlusion of the lower limbs

The presence of ischaemic tissue excites an inflammatory reaction and synth esis of acute phase proteins (APhPs). Ceruloplasmin (Cp) protein binds 90% of the copper in plasma and it is one of the positive APhPs, and its concen tration increases in infection, inflammation or necrosis. The study present s the relationship of the oxidase activity of Cp and concentrations of Cu a nd Zn in serum of men with different degrees of ischaemia of the lower limb s. The subjects were 32 men with chronic arterial occlusion (AO) of the low er limbs. The oxidase activity of Cp was measured in serum with o-dianisidi ne as a substrate. Concentrations of Cu and Zn were determined by using ato mic absorption spectrometry. The mean activity of Cp in serum in AO (173+/- 69.2 U/l) was higher as compared with the control group (123.7+/-28.6 U/l), and in men with critical ischaemia (>194.8 U/l) than in men with a moderat e level of ischaemia (109.31+/-31.6 U/l). The mean concentrations of Cu and Zn in serum were found to be higher in AO (22.2+/-4.2 and 19.1+/-6.9 mu mo l/l, respectively) than in the control group (16.3+/-1.8 and 15.2+/-2.3 mu mol/l), and in men with critical ischaemia (greater than or equal to 22.2 a nd 19.1 mu mol/l) than in men with a moderate level of ischaemia (18.5+/-3. 3 and 14.5+/-4.3 mu mol/l). Significant positive correlation coefficients w ere calculated for the activities of Cp and concentrations of Cu in the con trol group (r=0.86) and the AO group (r=0.76), and low, but significant, co rrelations for Cp and Zn in the AO group (r=0.66). The increase in the oxid ase activity of Cp and concentration of Cu in serum in ischaemia is caused by the acute phase response. The relationship of Zn concentration and Cp ac tivity in ischaemia is indirect and needs further study.