Water Exchanges and Barriers as Studied by the Use of Hydrogen Isotopes

Publisher Website
Google Scholar
Abstract
A review of present knowledge of water movement into, within, and out of biological organisms. No great difference between the rate of diffusion of H2O, HDO, and HTO molecules across biological barriers is in evidence. Water exchange studies between the animal organism and the external environment using HDO and HTO as tracers show (a) the exchange of water between the inspired air and body fluids in the lungs is nearly 100%, (b) the amt. of water transferred from the gastrointestinal tract to the blood stream following ingestion is linear with time, (c) a permeable barrier exists in the outer skin through which water vapor may diffuse in both directions, and (d) after equilibrium is attained in body fluids, all fluids lost from the body contain, within the measuring sensitivity, the same isotopic concn, of HDO or HTO as that prevailing in body fluids at the time of loss. HDO or HTO introduced into the blood stream normally attains about 98% of equilibrium in man in an hr. indicating very rapid water exchange between vascular and all extravascular fluids.

This publication has 12 references indexed in Scilit: