title: Increase in the ratio of 18S RNA to 28S RNA in the cytoplasm of mouse tissues during aging.
abstract: The possibility of alterations in cytoplasmic RNA in mouse liver, kidney and brain during aging was investigated. The cytoplasmic RNAs in these organs gave similar profiles of optical density at 260 nm with three major peaks at 28S, 18S and 4S on sucrose gradient centrifugation. However, the ratio of the amounts of 18S and 28S RNA increased significantly with age in the brain and liver. The polyacrylamide gel electrophoretic patterns of extracts of the three tissues under both native and denaturing conditions were nearly identical regardless of the age of the animals. Since most of the minor components separated on gels were probably in vivo degradation products of ribosomal RNA, these results suggest that the extent of apparent and hidden breaks in ribosomal RNA does not change during aging.
mesh_terms: D000375:Aging; D000818:Animals; D003593:Cytoplasm / Q000032:analysis / Q000648:ultrastructure*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D012313:RNA / Q000032:analysis / Q000096:biosynthesis*
chemical_list: D012313:RNA