Factors involved in increased protein synthesis in rat kidney after administration of DDT

Abstract

Homogenates of kidney cortex obtained from control rats and rats treated with DDT have been separated into microsomes or ribosomes, and into postmicrosomal (S105) supernatant fraction or pH 5 supernatant fraction. The incorporation of [ 14C]phenylalanyl-tRNA into peptide was increased when microsomes derived from kidneys of DDT-treated rats were incubated with pH 5 supernatant fraction from control rats. Elongation factors (EF) 1 and 2, necessary for the binding of aminoacyltRNA to ribosomes and for translocation of peptidyl-tRNA from the A site to the P site of ribosomes, were present in the pH 5 supernatant fractions of kidney of control and DDT-treated rats and these fractions were incubated with KCl-washed ribosomes obtained from livers of control rats. The results provided evidence that the increased incorporation observed with the pH 5 supernatant fraction obtained from the DDT-treated animals could not be attributed to decreased ribonuclease activity or to increased elongation factor 2 activity but was due to an increase in elongation factor l activity.