Construction of Hemoglobin-vesicle with long-term in vivo oxygen transporting ability

血红蛋白囊泡(HBs)包裹着可与氧可逆结合的血红蛋白(Hb)在磷脂囊泡(脂质体)中起到人工氧载体的作用。然而，当中心铁从两价氧化到三价时，Hb失去了氧结合能力(metHb形成)。在这种现象中，通过一个电子从中心铁转移到结合氧而形成的metHb(自氧化)和由所产生的活性氧(过氧化氢)进一步形成的metHb是连续发生的。我们发现a(metHb，Hb/L-酪氨酸)系统能迅速清除过氧化氢。本研究证实了以L酪氨酸为底物的利用过氧化氢酶活力的过氧化氢清除体系对抑制高铁血红蛋白的生成是有效的。此外，我们证实，即使在H-…中连续加入过氧化氢，将该体系包含在其内水相中也能显著抑制乙肝病毒metHb的形成。BV离散度更大。给大鼠灌胃20ml/kg的乙肝病毒分散体后，其MetHb形成的半衰期由传统的14小时延长至44小时。此外，从一种新的筛选方法中测量了铁基Hb自由基与Tyr以外的14种候选物质的反应速度，我们发现一些具有Indore环的衍生物，如色氨酸或羧基，其抑制作用强于Tyr。另一方面，对于羰基Hb(HbCO)，不存在自氧化生成MetHb的现象。如果我们利用血液循环中HbCO逐渐转化为HBO_2的现象，我们可以通过抑制含有HbCO的乙肝病毒的metHb的形成来维持携氧能力。在本研究中，我们测量了含有HbCO的乙肝病毒的metHb形成率的变化，并阐明了尽管HbCO的比例不同，但从剩余的HBO_2中得到的metHb比率是相同的。因此，建议在消除HbCO中CO的同时，构建温和的MetHb生成系统。如上所述，如果这两种方法配对，有望通过体内有效地控制乙肝病毒的metHb形成。较少

The hemoglobin vesicles (HbV) encapsulating hemoglobin (Hb), which binds oxygen reversibly, in the phospholipid vesicle (liposome) function as an artificial oxygen carrier. However, Hb loses an oxygen binding capacity when central iron is oxidized from two valences to three (metHb formation). In this phenomenon, metHb formation (autoxidation) by one electron transfer from the central iron to the bound oxygen and the further metHb formation by the resulting reactive oxygen (peroxide) are taken place in a row. We have found out that a (metHb Hb/L-tyrosine) system eliminates peroxide promptly. In present study, it was confirmed that the hydrogen peroxide elimination system utilizing the peroxidase activity of metHb which uses L-tyrosine as a substrate was effective for suppression of metHb formation. Moreover, we confirmed the remarkable suppression of metHb formation of HbV which included this system in their inner aqueous phase, even if hydrogen peroxide were continuously added to the H … More bV dispersion. When the 20mL/kg of the HbV dispersion was administrated into rats, the half time of metHb formation in this HbV extended till 44 hours in comparison with 14 hours of the conventional HbV. Furthermore, from a novel screening method which measured the reaction rate of ferryl Hb radical with 14 kinds of candidate substances other than Tyr, we found that some derivatives which possesses indore rings such as tryptophane or carboxyl groups showed the suppressive effect higher than Tyr.On the other hand, metHb formation caused from autoxidation does not occur for carbonyl Hb (HbCO). And if we use the phenomenon of the gradual conversion of HbCO into HbO_2 in blood circulation, we can maintain an oxygen carrying capacity by suppressing the metHb formation of HbV containing HbCO. In present study, we measured the change of the metHb formation rate of HbV containing HbCO and clarified that the rate of metHb from the remaining HbO_2 was the same in spite of the differed portion of HbCO. Therefore, it is suggested that gentle metHb formation system can be constructed in accompanied with the elimination of CO from HbCO. As mentioned above, if these dual approaches are paired, it is expected that the metHb formation of HbV can be effectively controlled by in vivo. Less