Metabolic studies on the sugars of nucleic acids III. 14C-labelling of ribose and deoxyribose in rat tissues in vivo

Abstract

• 1.

  1. [¹⁴C₆]Glucose was injected intravenously into rats and the incorporation of ¹⁴C into the ribose and deoxyribose of nucleic acids was investigated.

• 2.

  2. In the RNA of all tissues studied, namely, thymus, spleen, liver and intestinal mucosa, the incorporation into the purine-bound ribose was higher than that into the pyrimidine-ribose. Further analysis showed that the specific activity of the ribose attached to cytosine was the lowest of the values for the four individual nucleotides; this was especially marked in the thymus.

• 3.

  3. Similarly in the DNA, the specific activities of the deoxyribose moieties bound to the two purine bases were greater than the corresponding values of the pyrimidine-deoxyribose.

• 4.

  4. These findings are in agreement with the results obtained previously from similar investigations in vitro. They are discussed here with reference to the formation of deoxyribotides from their respective ribose analogues.