To increase the amount of oxygen transported by Hb-vesicles, it is important to suppress metHb formation. α-Tocopherol decreased lipid peroxidation in Hb-vesicles composed of EYL, whereas the Hb-vesicles composed of saturated phospholipids, such as DPPC, showed less metHb formation. To suppress metHb formation in a highly purified Hb solution, glutathione (GSH) was studied as a reductant. GSH is oxidized not only by metHb reduction but also by O2 to generate active oxygen species, which react with Hb to form metHb. Effective nonenzymatic metHb reduction was observed at a high [Hb] because of the acceleration of metHb reduction, and at lower partial pressure of O2 (pO2) because of suppression of GSH oxidation. Hb-vesicles encapsulating 40 g/dl Hb with pyridoxal 5'-phosphate showed high oxygen transporting efficiency. The rate of metHb formation at a low pO2 in the blood stream was decreased by GSH.
|Japanese Journal of Artificial Organs
|Published - 1994 1月 1
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