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

Hemoglobin molecules were studied by stationary and rime-resolved laser abs orption 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 oxyg enation of hemoglobin with an initial methemoglobin concentration of 3% or lower is described by a two-exponential function. The rate parameters of th e reaction are independent of the radiation history and of the amount of su bunits oxidized by sodium nitrite, which is as high as approximate to 50% r elative to the total number of protein subunits.