Identification of T-kininogen in rat urine

Studies were carried out in order to characterize the kininogen in rat urine. Rat urine contained a component which was cross-reactive with antibody to rat plasma T-kininogen. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of rat urine revealed a single antigenic band corresponding to the molecular weight of plasma T-kininogen. Induction of acute inflammation in rats by an injection of lipopolysaccharide caused an increase in the urinary excretion of immunoreactive T-kininogen in parallel with an elevation of plasma T-kininogen. Kininogen partially purified from rat urine by affinity chromatography using S-carboxymethylated papain-agarose liberated only T-kinin upon trypsinization, but not upon treatment with rat glandular kallikreins. From these results, we conclude that T-kininogen is the major kininogen present in rat urine.