Protein synthesis in rat cardiac myocytes is stimulated at the level of translation by phorbol esters.

12-O-Tetradecanoylphorbol 13-acetate acutely stimulated the rate of protein synthesis maximally by about 43% in terminally differentiated myocytes freshly isolated from adult rat hearts. Stimulation was rapidly expressed (within 20 min). The relative effects of four phorbol esters on protein synthesis was consistent with a specific effect on protein kinase C. Inhibition of transcription with actinomycin D had no effect on the absolute stimulation of the protein synthesis rate by 12-O-tetradecanoylphorbol 13-acetate. We conclude that protein kinase C may be involved in the regulation of the translational process.