Regulation of mammalian protein synthesis in vivo. Protein synthesis in rat liver and kidney after the administration of sublethal doses of cyclohyximide.

Protein synthesis in vivo was studied at various times after the administration of sublethal doses of cycloheximide to rats. Cycloheximide caused an inhibition, followed by a dose-and time-dependent stimulation, of incorportation of labelled precursor into proteins of the liver and kidney. The stimulation of protein synthesis at 24h was not due to a change of precursor pool or the specific radioactivity of the precursor used. During the stimulatory period, leucine incorporation into various cellular protein fractions varied; incorporation into total nuclear protein was the most affected.