title: Measurement of free ammonia produced by X irradiation of glycylglycine in aqueous solution.
abstract: This research was initiated to test the validity of predictions based on Monte Carlo calculations of the effect of ionizing radiation on a simple dipeptide. The mechanism for the formation of ammonia, proposed by Garrison, Sokol, and Bennett-Corniea (Radiat. Res. 53, 376-384, 1973), was reevaluated by measuring the yields under deoxygenated and oxygenated conditions. Although free ammonia was formed under both conditions, the yields were different, depending on the concentrations of solute and molecular oxygen. The reaction probabilities of the specific interactions of free radicals formed in pure water with solute and oxygen are discussed to account for the observed difference. Our results obtained after low-dose-rate X irradiation are compared with those obtained by Garrison et al. after high-dose-rate 60Co gamma irradiation.
authors.affiliation: Health and Safety Research Division, Oak Ridge National Laboratory, Tennessee 37831.
authors.forename: H
authors.initials: H
authors.lastname: Yoshida
authors.forename: W E
authors.initials: WE
authors.lastname: Bolch
authors.forename: K B
authors.initials: KB
authors.lastname: Jacobson
authors.forename: J E
authors.initials: JE
authors.lastname: Turner
mesh_terms: D000641:Ammonia; D004151:Dipeptides / Q000528:radiation effects*; D006033:Glycylglycine / Q000528:radiation effects*; D009711:Nucleotides / Q000378:metabolism; D011854:Radiochemistry; D012996:Solutions
chemical_list: D004151:Dipeptides; D009711:Nucleotides; D012996:Solutions; D006033:Glycylglycine; D000641:Ammonia