title: Prekallikrein activation in human, bovine, and rabbit plasmas: presence of an inhibitor in bovine plasma.
abstract: Contact of human plasma with a negatively charged surface such as dextran sulfate activates prekallikrein to kallikrein, which releases the vasoactive peptide bradykinin from high-molecular-weight kininogen. The dextran sulfate-induced activation of prekallikrein at 0 degree C (assayed by its amidolytic activity on the chromogenic substate S-2302) could not be observed in either bovine or rabbit plasmas when compared to human plasma. Neither bovine nor rabbit plasma inhibited the amidolytic activity of contact-activated human plasma at 0 degrees C. The activation of prekallikrein in human plasma was significantly inhibited by the addition of bovine plasma but not by rabbit plasma. Bovine plasma (0.025 units, 1 unit = 1 ml of plasma) caused 68.8% inhibition of prekallikrein activation. Eighty percent of the inhibitory property of bovine plasma was present in the greater than 30,000-molecular-weight fraction. These results indicate the presence of an inhibitor(s) of prekallikrein activation in bovine plasma.
authors.affiliation: Department of Anatomy, Physiological Sciences, and Radiology, College of Veterinary Medicine, North Carolina State University, Raleigh 27606.
authors.forename: K M
authors.initials: KM
authors.lastname: Weerasinghe
mesh_terms: D000818:Animals; D002417:Cattle / Q000097:blood*; D002863:Chromogenic Compounds / Q000378:metabolism; D016264:Dextran Sulfate / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D005174:Factor XII / Q000037:antagonists & inhibitors; D006801:Humans; D007610:Kallikreins / Q000378:metabolism; D009842:Oligopeptides / Q000378:metabolism; D011288:Prekallikrein / Q000378:metabolism*; D011817:Rabbits / Q000097:blood*; D013045:Species Specificity
chemical_list: D002863:Chromogenic Compounds; D009842:Oligopeptides; C026148:prolyl-phenylalanyl-arginine-4-nitroanilide; D005174:Factor XII; D016264:Dextran Sulfate; D011288:Prekallikrein; D007610:Kallikreins