Authors: Somlyai G, Jancsó G, Jákli G, Vass K, Barna B, Lakics V, Gaál T.
Febs Lett. 1993 Feb 8;317(1-2):1-4.
In nature the ratio of deuterium to hydrogen (D/H) is about 1:6600; this means that the natural concentration of D is about 150 ppm (0.015 atom %). A worldwide survey of hydrogen isotopes in precipitation revealed [1,2] that the D content covers a range of 120 and 160 ppm depending mainly on the site of sampling and there are several indications that the D/H ratio is not constant in living organisms either .
The effect of the replacement of hydrogen with deuterium in biological systems is well documented (e.g. [3,4]), however, the possible role of naturally occurring D in the living organism has never, so far as we are aware, been investigated.The role of naturally occurring D in living organisms has been examined by using deuterium-depleted water (30-40 ppm D) instead of water containing the natural abundance of D (150 ppm).
The deuterium-depleted water significantly decreased the growth rate of the L, fibroblast cell line, and also inhibited the tumor growth in xenotransplanted mice. Eighty days after transplantation in 10 (59%) out of 17 tumorous mice the tumor, after having grown, regressed and then disappeared. We suggest that the naturally occurring D has a central role in signal transduction involved in cell cycle regulation.