红细胞作载体的谷胱甘肽过氧化物酶和超氧化物歧化酶对脑缺血再灌注的影响

GSH·Px or SOD encapsulated erythocytes in the study of cerebral ischemia reperfusion

目的研究采用红细胞（ＲＢＣ）作为超氧化物歧化酶（ＳＯＤ）和谷胱甘肽过氧化物酶（ＧＳＨ·Ｐｘ）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和ＧＳＨ·Ｐｘ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。结果被装入的ＳＯＤ和ＧＳＨ·Ｐｘ的ＲＢＣ，在兔体内的循环半寿期分别为１３．７±１．０天和７．３±２．５天，兔自身ＲＢＣ的值为１３．４±１．５天。对照组血浆ＮＯ浓度在再灌注１０分钟时达最高值。ＲＢＣ－ＳＯＤ组在再灌注４．５小时期间，ＮＯ持续较高浓度状态。ＲＢＣ－ＧＳＨ·Ｐｘ组和联合给药组在再灌注期间，ＮＯ浓度的升高受到抑制。在再灌注期间，对照组和ＲＢＣ－ＧＳＨ·Ｐｘ组的ＬＰＯ升高，ＲＢＣ－ＳＯＤ组和联合给药组的ＬＰＯ无明显升高。ＴＴＣ染色结果表明，ＲＢＣ－ＳＯＤ、ＲＢＣ－ＧＳＨ·Ｐｘ和ＲＢＣ－ＳＯＤ＋ＲＢＣ－ＧＳＨ·Ｐｘ可有效减轻脑缺血—再灌注损伤。结论ＲＢＣ可用作ＳＯＤ和ＧＳＨ·Ｐｘ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。

Objectives To study the practicability of using red blood cells(RBC)as the carrier of SOD or GSH·Px and to observe the effects of RBC SOD and RBC GSH·Px on cerebral ischemia reperfusion(I R).Methods The method of hypotonic dialysis was used in encapsulating SOD or GSH·Px into rabbit RBC.The circulation half lives(T 1/2 )of RBC SOD and RBC GSH.Px were determined in rabbits by 51 Cr radiolabel.Lipid peroxidation(LPO)and nitric oxide(NO)in plasma and TTC staining of cerebrum were examined.Results T 1/2 was13.4±1.5days(n=6)for RBC,13.7±1.0days(n=5) for RBC SOD,and7.3±2.5days(n=5)for RBC GSH·Px.The concentration of NO reduced gradually as reperfusion continuing in control group,but it was in astate of significant increase in NO concentration during the4.5hours of reperfusion.in RBC SOD group.The increase of NO was inhibited by the administration of RBC GSH·Px or(RBC SOD+RBC-GSH·Px).The increase of LPO during cerebral I Rwas inhibited by RBC SOD or(RBC SOD+RBC GSH·Px).Staining with TTC showed that the RBC SOD,RBC GSH·Px and(RBC SOD+RBC GSH·Px)could effectively protect cerebrum For I Rdamage,especially the last one.Conclusion Using RBC as the carrier of SOD or GSH·Px is practicable.Intact RBC SOD and RBC GSH·Px could scavenge active oxygen produced during cerebral I R.