Relationship between the Ribosomal Alteration after Partial Hepatectomy and the Increase in Liver Protein Synthesis in Vivo

Partial hepatectomy in the rat is known to cause rises in the rates of incorporation by subcellular liver preparations of 3H-puromycin into nascent peptide and 'Gleucine into protein.The operation has also been shown to be followed by a rise in the rate of liver protein synthesis in ho.The kinetics of the three rises after partial hepatectomy are the same, suggesting that the changes are interrelated.The effects of actinomycin D on the rises were studied.When the antibiotic (5 pg per hour) was given immediately after partial hepatectomy, it blocked the appearance of the rises in vitro and in vivo and, as a function of dose, affected the three changes in an indistinguishable manner.When actinomycin (10 pg per hour) was given to partially hepatectomized animals after the rises had occurred, the reactivities in vitro and in viva were gradually reduced to the normal levels.The halfway points in the return to the normal levels were at 4 hours from the time of the first injection of the antibiotic.