title: Detection of DNA synthesis in intact organisms with positron-emitting (methyl- 11 C)thymidine.
abstract: (11)CO(2) produced in the Brookhaven 152-cm cyclotron was converted to formaldehyde, which in turn was used for the enzymatic conversion of deoxyuridine-5'-phosphate to [(11)C]thymidylate. Enzymatic treatment of the nucleotide with alkaline phosphatase gave [(11)C]thymidine.The preparation of [(11)C]thymidine from cyclotron-generated (11)CO(2) required 110 min (about 5 half-lives): 35 min for the synthesis of H(11)CHO, 25 min for the enzymatic conversion to [(11)C]thymidylate, 20 min for column chromatography, 5 min for phosphatase treatment, 10 min for evaporation, 2 min for filtration through an anion-exchange resin, and 13 min for miscellaneous manipulations.Positron-emitting [(11)C]thymidine and [(11)C]thymidylate were used for in vivo tracer studies of DNA synthesis in mice for periods of up to 3 hr. Findings with carbon-11 were consistent with earlier studies in which carbon-14 and tritium-labeled thymidine were used. For example, 3 hr after injection of [(11)C]thymidine, spleen DNA was labeled to a much greater extent than was liver DNA.
mesh_terms: D000469:Alkaline Phosphatase; D000818:Animals; D002247:Carbon Isotopes; D002854:Chromatography, Paper; D004247:DNA / Q000096:biosynthesis*; D004601:Elementary Particles; D004926:Escherichia coli / Q000201:enzymology; D007413:Intestinal Mucosa / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009132:Muscles / Q000378:metabolism; D013154:Spleen / Q000378:metabolism; D013936:Thymidine / Q000138:chemical synthesis / Q000378:metabolism*; D013942:Thymine Nucleotides / Q000138:chemical synthesis / Q000378:metabolism; D013950:Thymus Gland / Q000378:metabolism; D014500:Uracil Nucleotides
chemical_list: D002247:Carbon Isotopes; D013942:Thymine Nucleotides; D014500:Uracil Nucleotides; D004247:DNA; D000469:Alkaline Phosphatase; D013936:Thymidine