The role of ascorbate and histidine in fibrinogen protection against changes following exposure to a sterilizing dose of γ-irradiation

Abstract

Sodium ascorbate and histidine were employed to protect fibrinogen against modifications followed by a gamma-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 Aalpha and Bbeta 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 alpha-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.

The antihemostatic profile of vitamin C: Mechanisms that underlie the technical application of a physiological molecule

“…3). These data corroborate the data of Zbikowska et al [24] in which ascorbate reduced the fibrin polymerization from gamma-irradiated fibrinogen, while reducing the incorporation of carbonyl groups to the fibrinogen molecule. This leads to an effective protection of fibrinogen from gamma irradiation-induced oxidation.…”

Sterilisation of healthcare products by ionising radiation: sterilisation of drug-device products and tissue allografts

“…Subsequent studies, undertaken by the same team, using a 50 kGy dose and dry ice and focusing on protein degradation, in particular, on fi brinogen, and plasminogen, as well as on the coagulation and fi brinolytic activities of plasma, have confi rmed the relatively small protective effect of 50 mM ascorbate. Surprisingly, a much greater protective effect was observed for 50 mM histidine (Zbikowska et al ., 2007a(Zbikowska et al ., , 2007b.…”