The utilization in vivo of deuterio-C14-formate, labeled intramolecularly

Abstract The utilization of formate labeled in the same molecule i.e., intramolecularly, with deuterium and C 14 was investigated in the rat. The deuterium and the C 14 contents of the urinary formate and of the methyl groups of choline and creatine, derived from formate, demonstrated the absence of the hydrogen isotope effects noted in earlier experiments performed with precursors labeled in separate molecules with the isotopes of carbon and hydrogen.