红细胞作载体的超氧化物歧化酶对兔脑缺血再灌注损伤的保护作用

THE PROTECTION OF SUPEROXIDE DISMUTASE ENCAPSULATED IN ERYTHROCYTES AGAINST CEREBRAL ISCHEMIA-REPERFUSION INJURY IN RATS

目的研究采用红细胞（ＲＢＣ）作为超氧化物歧化酶（ＳＯＤ）的载体的可行性，并将这些载体ＲＢＣ用于兔的脑缺血—再灌注研究。方法采用低渗透析法将ＳＯＤ装进ＲＢＣ，测量装入量和载体ＲＢＣ在兔体内的循环半寿期。通过测量外周血浆脂质过氧化物（ＬＰＯ）和一氧化氮（ＮＯ），并做脑组织的ＴＴＣ染色来观察其作用效果。结果被装入ＳＯＤ的ＲＢＣ，在兔体内的循环半寿期为１３．７±１．０ｄ，兔自身ＲＢＣ的值为１３．４±１．５ｄ。对照组血浆ＮＯ浓度在再灌注１０ｍｉｎ时达最高值。ＲＢＣ－ＳＯＤ组再灌注４ｈ期间，ＮＯ持续较高浓度状态。在再灌注期间，对照组ＬＰＯ升高，ＲＢＣ－ＳＯＤ组ＬＰＯ无明显升高，ＴＴＣ染色结果表明，ＲＢＣ－ＳＯＤ可有效减轻脑缺血—再灌注损伤。结论ＲＢＣ可用作ＳＯＤ的载体，它们对活性氧引起的脑缺血再灌注损伤有较好的防治作用。

Objective To study the practicability of using red blood cells (RBC) as the carrier of SOD and to observe the effects of RBC-SOD on cerebral ischemia-reperfusion (I-R).Methods The method of hypotonic dialysis was used to encapsulate SOD into rabbit RBC.The circulation half-lives (1/2) of RBC-SOD were determined in rabbits by 51Cr radiolabel.Lipid peroxide (LPO) and nitric oxide (NO) in plasma and TTC staining of cerebrum were taken to assess the I-R injuries.Results 1/2 was 13.4±1.5 days (n=6) for RBC,13.7±1.0 day (n=6) for RBC-SOD.The concentration of NO reduced gradually as reperfusion continued in control and SOD groups,but it remained in a state of significant increase during the 4 hours of reperfusion in RBC-SOD group.The increase of LPO during cerebral I-R was inhibited by RBC-SOD.TTC staining showed that RBC-SOD could effectively minimize the cerebral I-R injury.Conclusion Using RBC as the carrier of SOD is practicable.Intact RBC-SOD could scavenge active oxygen produced during cerebral I-R to protect the cerebrum from I-R damage.