Authors: Sinyak, Y.; Turusov, V.; Grigroriev, A.; Yaridze, D.; Gaidadimov, V.; Antoshina, E.; Gorkova, T.; Truhanova, L.
Published in: 34th Cospar Scientific Assembly, The Second World Space Congress, held 10-19 October, 2002 in Houston, TX, USA meeting abstract
The interplanetary space flights, Martian program as an example, will take place under conditions of increasing radiation level on crew. The search of methods for a decrease of oncologic risk produced by irradiation of astronauts, is one of the major factors of a successful implementation of a flight program. One of such methods is a usage by crew of potable water with the reduced concentrations of a heavy stable isotope of hydrogen – deuterium, which can be obtained in the regenerative life support systems.
The heavy water (D2O) has toxic properties, distorting biochemical reactions in the cell, inhibiting process of DNA replication. It can be presumed that the replacement of deuterium in the water for protium will result in normalization of cell metabolism, reparation will take place and this will lead to the inhibition of tumor development. In this study the water with a decreased by 65% of deuterium was used. Antitumor properties of D 2-free water were studied with transplantable Lewis lung carcinoma in BDF1 strain of mice.
First results show that average time of appearance of the first nodules at the site of transplantation was 14 % longer in mice fed D 2-free water as compared to control. The tumor volume in the experimental group (decreased content of D2) was always lower than in the control. Statistically significant differences in the tumor volume were registered at the 13, 15, 23, 26 and 28 -th days after transplantation. Inhibition of tumor growth was equal to 100% and 51% at the 5-th and 15-th days after- transplantation respectively. Increase of life span in the experimental group was 10%.
The results indicate that the use by astronauts of water with decreased content of deuterium may decrease the risk of oncological diseases under conditions of high radiation level in the flight to Mars.