Abstract
A preliminary study of the clinical application of enzyme-immunoassay (EIA) for insulin is reported. The insulin ETA kit, using the sandwich method with anti-insulin serum sensitized plastic beads as the solid phase and horseradish peroxidase as the labeling enzyme, was kindly supplied by Mochida Pharmaceutical Co. (Tokyo, Japan). The kit had a working range of 5 to 320 μU/m/ and gave good reproducibility. Blood samples were taken from 47 patients ((I) 20 diabetics treated with diet alone, (II) 10 diabetics treated with sulfonylurea oral hypoglycemic compounds, and (III) 17 non-diabetics) given 50 g-OGTT. The samples were analyzed for serum insulin by EIA and radioimmunoassay (RIA). The correlation coefficients between the values determined by RIA (X) and EIA (Y) were;(I) r=0.93, (II) r=0.78, (III) r=0.92, and for the total samples, r=0.91. A regression equation of Y=0.872 X+3.51 μU/m/ was obtained. ETA obviates the disadvantages associated with the measurement and handling of radioisotopes in RIA, and expensive equipment is not required. Based on the above findings, the insulin ETA kit is recommended for routine analysis of serum insulin.
