Saliva-Serum Ratios of Deuterium Oxide after Administration of Heavy Water

Abstract

TOTAL body water may be estimated by administering a known weight of deuterium oxide and, after equilibration has occurred, determining its concentration in water obtained from some body fluid. Faller et al. ¹ have shown that, within the limits of experimental error, the same values are obtained for total body water whether the deuterium oxide is administered orally or intravenously. Serum is the usual source of body water containing the equilibrium concentration of deutrium oxide. If, however, urine or saliva could be used, the whole procedure could be carried out without venipuncture; this would be an advantage when serial estimations are to be made or when other investigations involving venipuncture are undertaken in the same subject.