title: Age related changes in total DNA and RNA and incorporation of uridine and thymidine in rat brain.
abstract: 1. Total brain DNA and total brain RNA and the incorporation of thymidine[14C] and uridine[3H] were measured in young and aged rats. 2. From 20 days to the time of sexual maturation, both DNA and RNA levels increase. Total RNA exceeds total DNA at all ages. Comparatively, the ratio of total DNA/RNA is higher in young than in aged animals. 3. The incorporation of thymidine[14C]/g of DNA and of uridine[3H]/g of RNA decreases with age. This decrease is rapid in young animals. After 350 days of age, the incorporation becomes very low. The significance of data is discussed.
mesh_terms: D000375:Aging; D000818:Animals; D001923:Brain Chemistry; D004247:DNA / Q000378:metabolism*; D008297:Male; D012313:RNA / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013936:Thymidine / Q000378:metabolism; D014529:Uridine / Q000378:metabolism
chemical_list: D012313:RNA; D004247:DNA; D013936:Thymidine; D014529:Uridine