Age-associated changes in activities of rat hepatocytes. I. Protein synthesis

Experiments involving simultaneous comparisons of cells from two animals establish an age-dependent decline in protein synthesis. Specific radioactivities of fractions from cells of aged animals (20+ months) are depressed 60% to 80% versus those from younger animals (2 to 14 months). Isotope ratio patterns derived by PAGE indicate that formation of a 20000 MW polypeptide of cytoribosomal origin is even more strongly and specifically depressed.