Peptide formation during kidney regeneration following the administration of folic acid to rabbits and rats

Abstract

1. 1. The administration of folic acid to rabbits resulted in a kidney growth response similar to that reported for rats and mice. Kidney homogenates were separated into fractions: postmitochondrial supernatant fraction, microsomal fraction, microsomal salt wash fraction, postmicrosomal supernatant fraction and pH 5 supernatant fraction. All of the fractions except the latter one showed significant increases in the incorporation of [ 14C]phenylalanyl-tRNA peptide. 2. 2. This result contrasted with that obtained using folic acid-treated rats since, in regenerating rat kidney, the pH 5 supernatant fraction was very much more active than in control kidney. 3. 3. Elongation factor 1, but not elongation factor 2, when used to supplement the assays, abolished the differences between control and treated preparations. 4. 4. Further studies of the kidney of rabbits that had received folic acid showed that the binding to ribosomes both of phenylalanyl-tRNA and methionyl-tRNA fMet were elevated in homogenate fractions containing the initiation and elongation factors for translation.