T H E Production of Hydrogen Peroxide by High Oxygen Pressures* by Daniel L. Gilbert, Rebeca Gerschman, K. Barclay Ruhm,

Hydrogen peroxide is formed in solutions of glutathione exposed to oxygen. This hydrogen peroxide or its precursors will decrease the viscosity of polymers like desoxyribonucleic acid and sodium alginate. Further knowledge of the mechanism of these chemical effects of oxygen might further the understanding of the biological effects of oxygen. This study deals with the rate of solution of oxygen and with the decomposition of hydrogen peroxide in chemical systems exposed to high oxygen pressures. At 6 atmospheres, the absorption coefficient for oxygen into water was about 1 em./hour and at 143 atmospheres, it was about 2 em./hour; the difference probably being due to the modus operandi. The addition of cobalt (H), manganese (II), nickel (II), or zinc ions in glutathione (GSH) solutions exposed to high oxygen pressure decreased the net formation of hydrogen peroxide and also the reduced glutathione remaining in the solution. Studies on hydrogen peroxide decomposition indicated that these ions act probably by accelerating the hydrogen perioxide oxidation of glutathione. The chelating agent, ethylenediaminetetraacetie acid disodium salt, inhibited the oxidation of GSH exposed to high oxygen pressure for 14 hours. However, indication that oxidation still occurred, though at a much slower rate, was found in experiments lasting 10 weeks. Thiourea decomposed hydrogen peroxide very rapidly. When GSH solutions were exposed to high oxygen pressure, there was oxidation of the GSH, which became relatively smaller with increasing concentrations of GSH. When reduced glutathione solutions are exposed to high oxygen pressures, there is a significant production of hydrogen peroxide (1). If sodium desoxyribonucleic acid or sodium alginate were present in these solutions there was a decrease in viscosity which was attributed to reaction of these polymers with the hydrogen peroxide formed or its precursors (free radicals). These prooxidative effects of glutathione are inhibited by ethylenediaminetetraacetic acid disodium salt (EDTA) and thiourea. I t has been found that agents * This study was supported by funds provided under Contract AF 18(600)-556 with the School of Aviation Medicine, United States Air Force, Randolph Air Force Base, Texas. 989 J. Gm~. PHYsxol.., 1958, Vol. 41, No. $ The Journal of General Physiology on Jne 7, 2017 D ow nladed fom Published May 20, 1958