Effect of Ionizing Radiations on Distribution of Plasma Protein-Bound Neutral Hexoses in Mice and Dogs

Comparison of changes in concentration of protein-bound carbohydrates (PBC) as neutral hexoses in the plasma of C₃ H mice and beagles as a function of time after exposure to mixed gamma-neutron radiations revealed that the two species react similarly. The animals which died exhibited a marked increase in plasma PBC concentration while the survivors deviated only slightly from their preirradiation values. Analytical acrylamide-gel electrophoresis demonstrated that distinctive, progressive postirradiation changes occurred in the plasma of the animals which succumbed. The most striking changes were in the components tentatively identified as transferrin, haptoglobins, and α₂-macroglobulin. Preparative fractionation of plasma of both mice and dogs by combined molecular sieving and ion-exchange chromatography revealed that, in the four fractions uniformly obtained, absolute changes in PBC regularly occurred only in the first and third. The protein composition of these fractions and their significance as a prognostic tool in radiation injury are discussed. The suggestion that the preirradiation PBC concentration may constitute a crude index to radiosensitivity was confirmed under conditions specifically designed to test the thesis.