title: Protein synthesis studies in skeletal muscle of aging rats. II. In vitro studies with 0.5M potassium chloride washed polyribosomes.
abstract: To investigate further the age-related reduction in muscle protein synthesis activity found previously using a crude polyribosome/pH 5 system (Pluskal et al., 1984), a 0.5M KCl washing procedure was utilized to remove the nonribosomal factors from polyribosomes isolated from male Sprague-Dawley rats in the following age groups: young (1 to 2 months), mature (12 months), and aged (22 to 24 months). Using a common source of enriched elongation factor fraction from young animals, it was not possible to demonstrate any significant difference (p greater than .05) in protein synthesis between the 0.5M KCl-washed polyribosomes isolated from the various age groups. Using a cell-free system containing young salt washed polyribosomes stimulated by the addition of 0.5M KCl-wash fractions, however, it was shown that the mature and aged salt-wash fractions were less (p less than .05) active than material from young animals. Thus, the observed decline in protein synthesis efficiency during aging may be attributed to a reduced capacity to promote initiation/elongation by the nonribosomal salt wash fractions of muscle polyribosomes.
mesh_terms: D000375:Aging; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D002474:Cell-Free System; D066298:In Vitro Techniques; D008297:Male; D011132:Polyribosomes / Q000378:metabolism*; D011189:Potassium Chloride / Q000494:pharmacology; D014176:Protein Biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000596:Amino Acids; D011189:Potassium Chloride