Radioimmunological quantitation of urinary trypsin inhibitor.
Using monospecific antibody to human urinary trypsin inhibitor, we developed a highly specific and sensitive radioimmunoassay (RIA) for measuring human urinary trypsin inhibitor. No cross-reactivity of the antibody with protein standard serum, which contained albumin, alpha 1-antitrypsin, haptoglobin, alpha 2-macroglobulin, transferrin, IgG and IgA, was observed. The sensitivity of the system was 10 ng of trypsin inhibitor per assay tube, and 5-10 microliters of urine was sufficient to determine the concentration of trypsin inhibitor in urine. The amounts excreted in the urine of 10 healthy men and 10 healthy women were 4.83 +/- 2.46 (mean +/- SD) and 3.86 +/- 1.35 mg/day, respectively. The correlation between estimates by RIA and those by enzymic assay was r = 0.96 (p less than 0.005). The method proposed here can be used to determine the concentration of urinary trypsin inhibitor in a small amount of biological fluids and cells.
D000328:Adult; D001798:Blood Proteins / Q000276:immunology; D003429:Cross Reactions; D005260:Female; D006023:Glycoproteins / Q000276:immunology / Q000652:urine*; D006801:Humans; D008297:Male; D011863:Radioimmunoassay
D001798:Blood Proteins; D006023:Glycoproteins; C028665:urinastatin