An environmental chemical, polychlorinated biphenyl, increases the protein synthesizing activity of liver and kidney pH 5 supernatant fractions.

Homogenates of liver and of kidney cortex were obtained from control rats and from rats treated with the polychlorinated biphenyls (PCBs), Aroclor 1254, and were separated into ribosomes and into the postmicrosomal supernatant fraction. The latter fraction from liver and kidney was used to prepare the pH 5 supernatant fraction, containing elongation factors 1 and 2 (EF 1 and EF 2) for protein biosynthesis. These fractions were incubated with KCl-washed ribosomes obtained from control rat liver. The incorporation of [14C] phenylalanyl-tRNA into peptide was increased with the liver and kidney preparations derived from the treated rats. The elongation factor 1-dependent binding of [14C] phenylalanyl-tRNA to ribosomes was also markedly increased both with the liver and kidney preparations obtained from the rats that had received PCBs.