title: Role of water and ethanol radicals in the radiation destruction of human deoxyhemoglobin.
abstract: In this study destruction of human deoxyhemoglobin (deoxy-Hb) induced by the action of primary products of water radiolysis, mainly .OH, eaq-, H, and of secondary ethanol radicals was investigated. The extent of destruction was estimated on the basis of absorbance ratio A505/A563 after conversion of hemoglobin into methemoglobin (MetHb) and the changes in the parameters of hemoglobin oxygenation. Deoxy-Hb solutions were irradiated under the atmosphere of argon and N2O, in the absence and presence of ethanol. In each case the radiation-chemical yield for hemoglobin destruction Gd = sigma i fi gi was determined (where: fi--fractional efficiency of destruction by the individual radicals, gi-fraction of radicals reacting with deoxy-Hb). Results were elaborated statistically estimating, by the method of least squares, the parameters of a multidimensional regression function which for each experiment with deoxy-Hb conc. 5 mg ml-1 was of the form: Gd = 0.09 gOH + 0.018 geaq- -0.099 gH + 0.03 g R.Et. The destruction efficiencies f.OH and fR.Et were statistically significant while feaq- and fH were not.
mesh_terms: D000431:Ethanol / Q000528:radiation effects; D005609:Free Radicals; D006454:Hemoglobins / Q000528:radiation effects*; D006801:Humans; D066298:In Vitro Techniques; D010100:Oxygen / Q000528:radiation effects; D013053:Spectrophotometry; D014867:Water / Q000528:radiation effects
chemical_list: D005609:Free Radicals; D006454:Hemoglobins; D014867:Water; D000431:Ethanol; C100003:deoxyhemoglobin; D010100:Oxygen