Abstract 1. 1. The incorporation of [ 14C]leucine into protein was measured in liver preparations and blood of rats following the s.c. administration of methylmercury hydroxide (24 mg/kg body wt) or turpentine (5.0 ml/kg body wt). 2. 2. The translatability of the RNA obtained from polysomes in an mRNA-dependent reticulocyte lysate was elevated significantly in the preparations derived from the treated rats compared to control rats. 3. 3. Immunoprecipitation of the labelled translation products or of serum proteins showed that the mRNA activity and the synthesis of α 1-acid glycoprotein, an acute phase reactant, was elevated by the methylmercury treatment as well as by the turpentine-induced inflammatory response.