The Reversible Effect of Deuteration on Tissue Fluid and Biopolymers in Normal and Tumor Tissues of Mice

—The deuterium concentration in normal mice and mice inoculated with 4T1 mammary carcinoma has been studied by magnetic resonance imaging (MRI) and 1 H and 2 H contrast. Mice received deuterium (up to 10%) in drinking water. The reversible effect was observed when mice began to drink ordinary drinking water. The average period that is required to perform hydrogen/deuterium exchange in all parts of the mouse is 2.4 days. Hydrogen/deuterium exchange rates in normal and deuterated mice are not reliably distinguished. The day range for hydrogen/deuterium exchange in biopolymers depends on its localization in the mouse and varies from 8 to 24 days. The nonmonotonic character of the time dependence of the deuterium level was observed after a weekly consumption of drinking water with an increased deuterium content in the tumor. The median survival rate of the inoculated mice that received drinking water with an increased content of deuterium was 4 days longer than that in the control group.