Methemoglobin Reductase Activity of Nuclear Erythrocytes of the Sea Ruff (Scorpaena porcus, Linnaeus, 1758) under Normal and Oxidative Stress Conditions (In Vitro Experiments)
摘要
A method for evaluating the methemoglobin reductase activity of nuclear erythrocytes of teleost fish is proposed. This work was conducted on a bottom marine species (Scorpaena porcus, Linnaeus, 1758). In an in vitro experiment, an erythrocyte suspension of this type was resuspended in solutions with different concentrations of NaNO2; after washing off this compound, the process of methemoglobin (MetHb) reduction was studied for 150 min. The functional state of hemoglobin was judged by the results of spectral analysis. The study of the kinetics of MetHb reduction showed that the dependence was described well by the equation of an exponential function with a coefficient of determination (R2) greater than 0.9. The nature of the dependence remained at different levels of oxidative stress. This made it possible to calculate the velocity constant of the first order k (25°C). In this species, it was 5.75–6.45 (10–3) min–1, which slightly exceeded the known values for mammals, and was close to the data obtained for other species of bony fish. It was found that the MetHb-reductase activity of the nuclear erythrocytes of the sea ruff increased with a rise in the oxidative load. At a concentration of 6.0 mM NaNO2, it was 1.73 ± 0.21 µM MetHb min–1 g–1 Hb. It is assumed that this is due to the process of deoxygenation of hemoglobin.