title: A new direct radioimmunoassay of rat urinary kininogen.
abstract: A protein-binding radioimmunoassay (RIA) of rat low molecular weight (LMW) kininogen with the following characteristics has been developed: sensitivity, 2.5 ng/tube; inter-assay coefficient of variation, 12.4% (N = 28); and intra-assay coefficient of variation, 9.4% (N = 11). The new assay correlated (r = 1) with the determination of kinin equivalence of kininogen after trypsinization. The cross-reactivity of rabbit anti-rat LMW kininogen antibody was 2.5% with bovine LMW kininogen, 5.8% with rat plasma high molecular weight (HMW) kininogen, and none with kinin. Although the antibody appears to partially recognize des-kinin-kininogen, the low degree of cross-reactivity and the extremely low levels of kinin-free-kininogen allow accurate determination of total LMW kininogen in rat urines. The LMW kininogen formed 20% kinins with salivary kallikrein when compared with trypsin, suggesting that the preparation consists of both K- and T-kininogens (K = kallikrein susceptible; T = trypsin susceptible). The newly developed protein-binding RIA recognizes LMW kininogen of rat urine which consists of both K- and T-kininogens.
authors: Renal Section, Evans Memorial Department of Clinical Research, University Hospital, Boston, MA.
authors: N B
authors: NB
authors: Oza
mesh_terms: D000818:Animals; D007704:Kininogens / Q000276:immunology / Q000652:urine*; D007705:Kinins / Q000276:immunology; D008970:Molecular Weight; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D014357:Trypsin / Q000494:pharmacology
chemical_list: D007704:Kininogens; D007705:Kinins; D014357:Trypsin