Isotopic tracer studies on the biosynthesis of deoxyribose in the rat.

The biosynthesis of deoxyribose, in vivo, was studied with NaHIIC03 as a tracer, in normal adult, starved adult, normal newborn, "thiamine-deficient" adult and " tumor bearing" rats and in Yoshida ascites-tumor cells. Comparisons of the tracer patterns in ribose and deoxyribose isolated from the nucleic acids of skin and liver suggest that in young tissues the formation of deoxyribose may occur by direct reduction from ribose or via an intermediate common to ribose. The data obtained from the livers of young adults do not support this concept unless the pattern of 14C in the ribose which is the precursor of deoxyribose, is different from that of the ribose isolated from the RNA. The presence of an ascitic tumor in the young adult seems to influence pentose metabolism in the host liver.