Increased calmodulin synthesis in the pre-replicative phase of rat liver regeneration.

A cytosolic calmodulin wave has been described in the pre-replicative phase of rat liver regeneration. Here we demonstrate that this calmodulin increase is reduced by injection of cycloheximide (translation inhibitor) and actinomycin D (transcription inhibitor). In addition, we found that calmodulin mRNA levels are increased during the early pre-replicative period of liver regeneration, and this increase is affected by actinomycin D. Together, these results strongly indicate that the calmodulin wave observed in the pre-replicative phase of liver regeneration is due to de novo synthesis of this protein.