Laser kinetic spectroscopy of the oxygenation and oxidation of hemoglobin by nitrite in rats exposed to γ-radiation

Hemoglobin molecules were studied by stationary and time-resolved laser absorption spectroscopy. On the basis of these results, the kinetic parameters of oxygenation in the course of methemoglobin formation under the combined action of radiation and sodium nitrite were analyzed. The kinetics of oxygenation of hemoglobin with an initial methemoglobin concentration of 3% or lower is described by a two-exponential function. The rate parameters of the reaction are independent of the radiation history and of the amount of subunits oxidized by sodium nitrite, which is as high as ≈50% relative to the total number of protein subunits