Soluble factors of protein synthesis in rat liver during the acute-phase reaction.

Cell sap of liver cells from rats undergoing an acute-phase reaction has an increased capacity for binding leucine to tRNA. This increased capacity does not depend on concurrent changes in the leucine pool. The kinetics of activity of leucyl-tRNA synthetase from acute-phase cell sap do not show relevant differences from the normal. Acute-phase cell sap contains more tRNA than its normal counterpart. Experiments performed with increasing amounts of exogenous deacylated tRNA demonstrate that under our experimental conditions the observed higher concentration of tRNA in acute-phase cell sap could explain the increased activity in leucine incorporation into leucyl-tRNA.