CHANGES IN SERUM LEVELS OF SIALOGLYCOPROTEINS IN MICE EXPOSED TO UV-BRADIATION

In the acute phase reaction, hepatocytes in the liver are activated an d increase the plasma levels of acute phase reactants. Our previous st udy has shown that plasma sialic acid, an acute phase reactant, was in creased following exposure of mice to UV-B radiation. Plasma sialic ac id is derived from many plasma components. To clarify the type of plas ma sialic acid that is increased by exposure to UV-B radiation, we per formed two-dimensional electrophoresis and staining for sialic acid. C onsequently, the increases in haptoglobin and hemopexin were marked an d 90% or more of the increased sialic acid was derived from these two glycoproteins after exposure to UV radiation. The increase in alpha(1) -acid glycoprotein levels was slight and did not contribute to the tot al increase in plasma sialic acid after exposure to UV radiation, Plas ma levels of several proteins including antichymotrypsin (ACT), were r educed following exposure to UV radiation. The discrepancy between our results and published ones regarding ACT levels are discussed in term s of the type of cytokine.