SIMPLIFIED RADIOIMMUNOASSAY OF BRADYKININ IN HUMAN-PLASMA

  • 1 January 1980
    • journal article
    • research article
    • Vol. 26  (3) , 429-432
Abstract
A greatly simplified radioimmunoassay for bradykinin in human plasma is described. Current techniques require multiple chromatographic steps or extraction procedures with analytical recoveries of bradykinin of often less than 60%. A method in which bradykinin is separated from components of higher relative molecular mass (including kininogens) in a single step, using a column of Sephadex G-25 medium (PD-10) is presented. The mean analytical recovery of [3H] bradykinin added to plasma is 85.5% (SD, 3.5%). The sensitivity of this radioimmuoassay is 25 pg per assay tube, equivalent to 125 ng/l of plasma. Twenty to 30 blood samples may be completely processed and assayed within 6 h. As determined with this technique, concentrations of bradykinin in plasma from apparently normal subjects ranged from 2.5-5.2 .mu.g/l (mean 4.2, SD 1.1 .mu.g/l); these values are consistent with previously reported normal values.