[Phenylephrine synchromizes rhythm of protein synthesis in hepatocyte culture]

Published data indicate that 1-3 microM adrenomimetic phenylephrine increases the concentration of calcium ions in the cytoplasm of cultured hepatocytes. We studied low-density cultures exhibiting no protein synthesis rhythm in the fresh medium and demonstrated that a 2 min action of 2 microM phenylephrine induces protein synthesis rhythm, i.e., synchronizes the synthesis oscillations in hepatocytes. A similar effect was observed for a selective inhibitor of the reticulum calcium pump, di-tert-butyl-benzohydroquinone, that increases the cytoplasm concentration of calcium ions by a receptor-independent mechanism. A calcium antagonist imipramine obviated the synchronization effect of phenylephrine. We propose that short-term changes in the cytoplasm concentration of calcium ions covering the whole cell population are among intracellular mechanisms of protein synthesis synchronization in hepatocytes in vitro.