Simple radiosensitizing of hypoxic tumor tissues by N2O/Br(-) mixture.

Abstract

The radiosensitization model of hypoxic tumor tissues based on the N2O/Br(-) mixture is described. The well-documented radiolysis of water in the presence of N2O and Br(-) ions at a low concentration supports this model. An aqueous solution saturated with N2O gas during the radiolysis generates OH radicals in a large extent. In N2O/Br- media at pH<9, Br2 is formed. Br2 hydrolyzes in an aqueous solution to form a very reactive hypobromous (HOBr) acid. Such process is described by the following chemical reaction: H2O + Br(-) + N2O + ionizing radiation (IR) --> HOBr + OH(-). In vivo formed HOBr as a long-lived product with a high biological activity induces the hypoxic tumor cell damage via many unique mechanisms. A local application or inhalation of an N2O-O2 mixture before or during the radiotherapy to enhance the saturation of tissues with N2O is a key prerequisite. Since the extracellular concentration of Br(-) ions is very low (0.02-0.05 mM), an oral or local application of NaBr should be used to shift the extracellular concentration of Br(-) ions to the mM region.

• Authors: P Billik
• Journal: Medical hypotheses (Med Hypotheses) Vol. 85 Issue 1 Pg. 37-40 (Jul 2015) ISSN: 1532-2777 [Electronic] United States
• PMID: 25812437 (Publication Type: Journal Article)
• Copyright: Copyright © 2015 Elsevier Ltd. All rights reserved.

Chemical References

• Radiation-Sensitizing Agents
• Nitrous Oxide
• Bromine

Topics

• Bromine (administration & dosage)
• Cell Hypoxia
• Humans
• Neoplasms (pathology)
• Nitrous Oxide (administration & dosage)
• Radiation-Sensitizing Agents (pharmacology)