In the present work the influence of hypoxia on black scorpionfish (Scorpaena porcus) nucleated red blood cells has been studied at in vivo (whole blood) and in vitro (cell suspension) experiments. Experiments were conducted in the range of oxygen concentration 0,3-8,5 mg О2 l-1, water temperature 14-16 оС, and the duration of exposure period was 4 h. Deep hypoxia (less than 2 mgО2 l-1) caused hemoglobin transition to a ferry-form (MtHb), and the most substantial increase of MtHb concentration was observed at severe hypoxic conditions (less than 1 mg О2 l-1). The highest MtHb level observed was 19-32 %. The results of in vivo and in vitro experimental series were similar, indicating that mechanisms involved in MtHb formation occur within cells and are not associated with organismic responses to oxygen deficiency. Moderate hypoxia (oxygen concentration more than 2 mg О2 l-1) did not cause hemoglobin transformation. MtHb formation did not influence the level of reactive oxygen species (DCF-DA fluorescence) and the integrity of cellular membrane (double staining with SYBR Green I and Propidium iodide) in red blood cells. The level of dead cells in control and experimental groups did not differ, indicating that responses observed were in the range of physiological norm.
Key words: hypoxia, experiments in vivo and in vitro, red blood cells, methemoglobin, flow cytometry