The Use of Nitrous Oxide in Elucidating Mechanisms of Radiosensitization in Chemical and Biological Systems

Abstract

Radiosensitizing effects of electron scavengers in aqueous solutions of aromatic compounds and of certain alkylating agents and organic nitroxide free radicals in suspensions of erythrocytes and bacteria are discussed. In neutral aqueous solutions of aromatic compounds the radiosensitizers exert their effect through: 1) interference with back reactions involving e^_aq and H, 2) interaction with solute radicals, and 3) conversion of e⁻sq, and H into oxidizing radicals.

For biological systems (erythrocytes and bacteria) radiosensitizing mechanisms of certain alkylating agents (iodoacetic acid and N-ethylmaleimide) and organic nitroxide free radicals are discussed in light of their ability to interact with e^_sq, OH and vital biological targets.

It is shown that N₂O is a useful tool in the elucidation of radiosensitizing mechanisms at the cellular and molecular level.

Key Words:

• Alkylating agents
• aminobenzoic acids
• benzoic acid
• e⁻_aq, OH, N₂O, O₂
• iodoacetic acid, N-ethylmaleimide: triacetone amine-N-oxyl
• organic nitroxide free radicals
• radical scavengers
• radiosensitization
• rapid mixing
• vitamin B₆