Thermal injury-induced expression of acute-phase proteins in rat liver

Relative changes in acute-phase protein and albumin mRNAs from the liver of rats exposed to sublethal and lethal scaldings were examined by hybridization and cell-free translation. Infliction of a sublethal scalding comprising 20 per cent of the total skin area resulted in a seven-fold increase of alpha 1-acid glycoprotein (AGP), alpha 1-cysteine protease inhibitor (CPI) and the alpha- and gamma-fibrinogens' (Fb) mRNAs, whereas the level of haptoglobin (Hp) mRNA increased three times. The simultaneous infliction of two such sublethal scaldings were lethal and accompanied by a significant decrease in the concentration of AGP while the levels of CPI. Hp and Fb mRNAs remained similar to those observed after a single 20 per cent injury. A 4 h time delay between the two scaldings was also fatal and followed by an additional increase in Hp mRNA concentration whereas the levels of the other mRNAs were close to those observed after a single 20 per cent scalding. These results demonstrated that the fatal effect of the second scalding was not related to any inhibition of acute-phase reactants mRNA synthesis in the liver.