title: Age-related changes in total DNA and RNA and incorporation of uridine and thymidine in rat liver, kidney and spleen.
abstract: Total content of DNA and RNA in liver, kidney and spleen were measured in young and aged rats. At the same time the incorporation of [14C]thymidine, a DNA precursor, and [3H]uridine, an RNA precursor, were also determined. Changes in total organ DNA and RNA correlated with sexual maturation as did incorporation of precursors. Young animals have more DNA per organ relative to RNA, with kidney and spleen DNA showing a decrease between maturity and senescence. However, liver RNA increases with age, a change probably due to decreased catabolism of RNA since [3H]urine uptake decreases. Liver polyploid differentiation, and [14C]thymidine and [3H]uridine uptake, are correlated. In kidney, incorporation of [3H]uridine is inversely related to [14C]thymidine incorporation.
mesh_terms: D000375:Aging; D000818:Animals; D004247:DNA / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008297:Male; D009928:Organ Specificity; D012313:RNA / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012741:Sexual Maturation; D013154:Spleen / Q000378:metabolism*; D013936:Thymidine / Q000378:metabolism; D014529:Uridine / Q000378:metabolism
chemical_list: D012313:RNA; D004247:DNA; D013936:Thymidine; D014529:Uridine