QUANTITATIVE AND QUALITATIVE CHANGES OF EXTRACELLULAR-SUPEROXIDE DISMUTASE IN PATIENTS WITH VARIOUS DISEASES

Extracellular-superoxide dismutase (EC-SOD) is a secretory glycoprotei n that is the major SOD isozyme in extracellular fluids. It has previo usly been shown that EC-SOD levels in sera from healthy persons are cl early divided into two discontinuous groups: a lower group (named Grou p I, below 120 ng/ml) and a higher group (Group II, above 400 ng/ml). The family studies have shown that the high EC-SOD level in healthy pe rsons is genetically transmitted. We report here on the EC-SOD levels in the sera of patients with various diseases. The EC-SOD levels were distinctly higher in patients with renal diseases and moderately highe r in liver diseases and diabetes than those in normal healthy persons. In cerebrovascular diseases, heart diseases and acute digestive disea ses, significant differences of EC-SOD were not observed. In patients with renal diseases, the increase of EC-SOD was accompanied by the lac k of renal function. Serum EC-SOD in Group I healthy persons is known to be heterogeneous with regard to heparin affinity and can be separat ed into three fractions: A without affinity, B with weak affinity and C with relatively strong heparin affinity, whereas the EC-SOD in Group II is mainly one fraction of C-type. Also in the case of hemodialysis patients, serum EC-SOD in Group I or Group I' (similar to 120-400 ng/ ml) was divided into three fractions. EC-SOD in Group II showed two di fferent profiles on heparin-Sepharose column chromatographies: one con sisted mainly of EC-SOD C and the other consisted of EC-SOD A and C. I t is probable that the high serum EC-SOD level in hemodialysis patient s was due to two possible factors: the genetic transmitted factor and unknown pathophysiological factor(s).