Ribosyl Transfer between Ribose Nucleotides in the Rat

Abstract

IN the course of studies on alterations in the rate of catabolism of nucleic acids induced by radiation after total body exposure of rats, evidence has been obtained of the existence of an exchange between the ribosyl residues of purines and pyrimidines and urinary imidazole acetic riboside. The latter riboside has served as a measure of the isotope concentration in the ribose pool of the rat. Hiatt et al. ¹ have reported recently an application of this ‘metabolic trap’ to the study of mechanisms by which glucose is metabolized in vivo, particularly with respect to the contribution of the glucose-6-phosphate oxidative shunt to the metabolism of glucose. The use of imidazole acetic riboside as a device for trapping ribosyl residues has been made possible by the findings of Tabor and his collaborators^2,3, who have demonstrated that imidazole acetic riboside is one of the major urinary excretion products of imidazole acetic acid.