Abstract
Like human kininogens-deficiency, the ureter urine of Brown Norway (B/N) Katholiek rat, a congenitally deficient strain in plasma high molecular weight (HMW)-and low molecular weight (LMW)-kininogen, showed no detectable kinin in the peptide fraction of gel chromatography, whereas normal ureter urine (B/N-Kitasato rat) expressed kinin in the peptide fraction, when assayed by bradykinin enzyme immunoassay (EIA). However there was immunoreactive substance in the higher molecular weight fraction in both strains of rat. The nature of this substance is not known, but it may give rise to a wrong estimate for kinin if rat urine is allowed to immunoassay directly, and peptide fraction of urine is not resolved into its components by gel chromatography. Kinin degrading activity in rat urine is so potent that kinin could be mostly degraded when stored in the bladder, since kinin was found in the peptide fraction of fresh ureter urine but not in that of bladder urine of the normal strain.
