Search

Aim: To investigate an effect of hypoxia on the formation of nitric oxide (NO) in the brain and blood of rats and an influence of L-NNA, the NO-synthase inhibitor, and sodium nitrite on NO generation in separate and simultaneous introduction of these compounds in the animal body., Material and Methods: Experiments were conducted on 42 rats of Krushinsky-Molodkina (K-M) line without adaptation to hypoxia and short-term adaptation to hypobaric hypoxia. Animals were intraperitoneally injected with sodium nitrite (0.5 mg/100 g) and the non-specific inhibitor of NO-synthase L-NNA (2.5 mg/100 g) at different times. Changes in NO content were assessed using electron paramagnetic resonance (EPR) by the intensity of nitrosyl Hb-NO complexes in ERP blood spectra., Results and Conclusion: The production of NO in the brain, compared with that in the blood, was significantly reduced, not only under physiological conditions, but also after the administration of moderate doses of NaNO2. In the short-term hypobaric hypoxia, there was the intensification of the processes of the reduction of NO2- to NO and the formation of nitrosyl heme-NO complexes not only in the blood but also in the mammalian brain.

Using electronic paramagnetic resonance (EPR), we studied the effect of the peptide cortexin on the content of hemoglobin nitrozyl complexes (Hb-NO-complexes) and other paramagnetic centers (transferrin, methemoglobin) in the blood of rats of Krushynsky-Molodkina line in the experimental hemorrhagic stroke induced by acoustic stress. After the acoustic exposure, the level of Hb-NO-complexes have increased by more than 6 times. The intensity of the EPR signal of the plasma peptide transferrin increased by 1,5 times. The level of blood methemoglobin was also elevated, though not significantly, after the acoustic stress. Cortexin substantially reduces the formation of Hb-NO-complexes and, therefore, the level of nitride oxide while the contents of transferrin and methemoglobin remain intact.