Polyribosomes in rat tissues. 3. The response of the polyribosome pattern of rat liver to physiologic stress.

Abstract

Summary The size distribution of polyribosomes prepared from the postmitochondrial supernatant of rat liver is modified by prolonged fasting, partial hepatectomy, and the administration of dinitrophenol or carbon tetrachloride. The carbon tetrachloride also causes the release of ribosomes bound to the endoplasmic reticulum, in addition to the extensive breakdown of the polyribosomes. The results suggest that the size distribution is not simply a function of the relative concentrations of the ribosomes and mRNA, 3 but rather depends on the energy supply and the relative sizes of the mRNA that is being produced. In general, the proportion of ribosomes sedimenting in the heavy polyribosome region appears to correlate with the predicted growth rate (protein synthesizing capacity) of the tissue.