Enzyme immunoassay for cuprozinc-superoxide dismutase in serum and urine.
A highly sensitive enzyme immunoassay system for the determination of cuprozinc-superoxide dismutase (Cu,Zn-SOD) in serum and urine by using beta-galactosidase as a labeling enzyme is reported. This assay had a greater sensitivity than that of previously reported radioimmunoassay methods and could measure from 0.05 to 10.0 ng of Cu,Zn-SOD with good reproducibility. Coefficients of variation for this enzyme immunoassay were 2.8-8.3% within a day and 5.6-16.1% between days. The average recoveries were 96-103% from sera and 96-105% from urines, respectively. Using this enzyme immunoassay, serum Cu,Zn-SOD concentrations increased significantly in patients with renal diseases and were slightly elevated in patients with liver diseases. Urinary Cu,Zn-SOD appeared to be the highest in all renal diseases. By immunofluorescent staining, Cu,Zn-SOD was located in the thickened portions of the glomerular basement membrane and proliferating mesangial cells of the kidney tissue from a patient with membranous glomerulonephritis.
D000818:Animals; D000917:Antibody Formation; D003404:Creatinine / Q000652:urine; D006801:Humans; D007124:Immunoenzyme Techniques; D007674:Kidney Diseases / Q000201:enzymology; D011817:Rabbits / Q000276:immunology; D013482:Superoxide Dismutase / Q000032:analysis*; D013997:Time Factors
D003404:Creatinine; D013482:Superoxide Dismutase