The effect of ACTH4-10 on protein synthesis, actin and tubulin during regeneration.

The effects of ACTH4-10, a peptide fragment of corticotropin, on rat dorsal root ganglia (DRG), spinal cord and sciatic nerve were studied following a crush lesion of the sciatic nerve. The in vitro total protein synthesis rate of DRG L4, L5 and L6, measured one and three days after ipsilateral nerve crush, were not altered by various ACTH4-10 treatment regimes. Likewise, neither ACTH4-10 treatment of sham-operated rats nor in vitro exposure of control ganglia to peptide, resulted in changes in synthesis rate. Four days after crush lesion, the amounts of actin and tubulin in the ventral horn L2-L5 region of the spinal cord and of actin in DRG L5 were estimated following 2-dimensional separation. No significant effect of ACTH treatment was found. Degeneration-associated changes in the protein profiles of segments of sciatic nerve were not altered by ACTH4-10 treatment. The data are discussed in relation to the possible site of action of neurotrophic ACTH-like peptides.