The role of ascorbate and histidine in fibrinogen protection against changes following exposure to a sterilizing dose of γ-irradiationZbikowska, Halina Malgorzata; Nowak, Pawel; Wachowicz, BarbaraBlood Coagulation & Fibrinolysis: October 2007 - Volume 18 - Issue 7 - p 669–676 doi: 10.1097/MBC.0b013e3282ced113 Original Articles Abstract Author Information Sodium ascorbate and histidine were employed to protect fibrinogen against modifications followed by a γ-irradiation process that could potentially inactivate the blood-borne viruses in plasma-derived products. Fibrinogen was irradiated (50 kGy total dose, on dry ice) using a 60Co source. Samples were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blot. Carbonyl groups were measured by the 2,4-dinitrophenylhydrazine-coupled method, and the fibrinogen clotting activity was assessed by different functional assays. In irradiated fibrinogen, the carbonyl group concentration was elevated three-fold versus control; and moderate fragmentation of largely Aα and Bβ chains was revealed. The rate of thrombin-catalyzed fibrinogen polymerization was inhibited (average 50%) with normal fibrinopeptide release and with a minor decrease of total clottable fibrinogen and α-polymer formation. Ascorbate reduced the incorporation of carbonyls to the fibrinogen molecule (by > 50% at 50 mmol/l; P < 0.001). Contrary to ascorbate, which alone delayed the fibrinogen polymerization rate, histidine abolished irradiation-induced inhibition of fibrinogen polymerization (by 80% at 50 mmol/l; P < 0.001). In conclusion, even though ascorbate effectively protects fibrinogen from oxidation due to its adverse effects on fibrinogen function, it may not serve as a suitable radioprotective. On the contrary, the first definite evidence is provided that radiation-sterilized fibrinogen in the presence of histidine greatly retains its clotting capability. Department of General Biochemistry, University of Lodz, Lodz, Poland Received 27 April, 2007 Revised 4 June, 2007 Accepted 6 June, 2007 Correspondence to Halina M. Zbikowska, PhD, Department of General Biochemistry, University of Lodz, Banacha 12/16 Street, 90-237 Lodz, Poland Tel: +48 42 635 44 82; fax: +48 42 635 44 84; e-mail: firstname.lastname@example.org © 2007 Lippincott Williams & Wilkins, Inc.