高原低氧习服大鼠红细胞变形性的变化规律及其分子机制

目的：探讨高原低氧习服大鼠红细胞变形性的变化规律及其分子机制。方法：将健康雄性大鼠随机分为3组（n=10）：常氧对照组、急性低氧组和低氧习服组。模拟高原低氧环境对大鼠分别进行急性低氧和间断低氧习服,麻醉后心脏采血,分别测定大鼠红细胞变形性、膜流动性、膜胆固醇和总磷脂含量、膜磷脂成分的含量、红细胞ATP酶活性、红细胞内Na＋和Ca2＋浓度及建立红细胞膜蛋白质双向电泳图谱,寻找差异蛋白质点,对其进行质谱鉴定。结果：①急性低氧大鼠红细胞变形性、膜流动性、膜胆固醇和总磷脂含量、红细胞ATP酶活性均降低;红细胞内Na＋和Ca2＋浓度均增高;红细胞膜磷脂酰丝氨酸（PS）、鞘磷脂（SM）含量增加,磷脂酰胆碱（PC）含量降低;建立了红细胞膜蛋白质双向电泳图谱,选取7个差异蛋白质点,其中4个在急性低氧后表达降低。②低氧习服大鼠红细胞变形性、膜流动性、膜胆固醇和总磷脂含量、红细胞ATP酶活性明显均增高;红细胞内Na＋和Ca2＋浓度均降低;红细胞膜PS、SM含量降低,PC含量增加;上述7个差异蛋白质点中4个在低氧习服后表达增高,3个表达降低,质谱技术鉴定结果为补体结合蛋白、水通道蛋白、膜攻击复合物抑制因子、葡萄糖运载体、脂质移行酶、氨基磷脂转移酶、依赖ATP的翻转酶,其中后三个酶与红细胞膜磷脂翻转有关。结论：急性低氧引起红细胞变形性、膜流动性、膜蛋白质表达、红细胞ATP酶活性及胞内Na＋和Ca2＋浓度方面相应的改变;经低氧习服后,上述指标有所改善,低氧习服对急性低氧引起红细胞的影响具有一定的保护作用;红细胞膜上的3种蛋白质,包括脂质移行酶、氨基磷脂转移酶和依赖ATP的翻转酶在低氧习服改善红细胞变形性的机制中可能发挥重要的作用。

Changes of erythrocyte deformability in rats acclimatized to hypoxia and its molemechanism

Objective： To observe the changes of erythrocyte deformability in rats acclimatized to hypoxia and its molemechanism.Me-thods： Male rats were randomly divided into three groups（n=10）： normal control group,acute hypoxia group and hypoxia acclimatization group.Animals were exposed to hypoxia for 0,1,28 d,blooded from their hearts after anaesthetized,respectively.Erythrocyte deformability,membrane fluidity,cholesterin and total lipid,lipid components of erythrocyte membrane,erythrocyte membrane ATPase and the concentrations of Na＋ and Ca2＋were measured respectively.The two-dimensional electrophoresis maps of the rats erythrocyte membrane protein were achieved.The different protein spots were founded by image master 2D elite and identified by mass spectrum. Results： ①In acute hypoxia group,the deformability,membrane fluidity,the content of membrane cholesterin and total lipid were declined.The content of phosphatidylserines（PS）,sphingomyelin（SM） in erythrocyte membrane lipids were increased,phosphatidylcholine（PC） reduced.The activity of ATP enzymes reduced and the concentration of Na＋ and Ca2＋ in erythrocyte increased.The two-dimensional electrophoresis maps of the rats erythrocyte membrane protein were achieved.Four of the seven protein spots selected increased and three of them showed no change.②In hypoxia acclimatization group,the deformability,membrane fluidity,the content of membrane cholesterin and total lipid were increased than those in acute hypoxia group,similar to normal group.The content of PS、SM in erythrocyte membrane lipids were reduced,PC increased.The activity of ATP enzymes induced and the concentration of Na＋ and Ca2＋ in erythrocyte increased after hypoxia acclimatization.Four of those protein spots mentioned increase and three declined after hypoxia acclimatization.They were respectively proved by mass spectrum to be alexin binding protein,aquaporin chip,membrane inhibitor reactive lysis,phospholipids scramblase,glucose transferase,aminophospholipid translocases,ATP-dependent floppase,the latter three proteins were associate with the overturning of erythrocyte membrane lipids.Conclusion： Acute hypoxia caused the corresponding damage of erythrocyte deformability,erythrocyte membrane fluidity,erythrocyte membrane proteins erythrocyte expression,the activity of membrane ATPase and the concentration of Na＋ and Ca2＋ in erythrocyte.The parameters above were improved after hypoxia acclimatization,so hypoxia acclimatization effected positively in the damage to erythrocyte due to acute hypoxia.The three membrane proteins might play important roles in the deformability improved by hypoxia acclimatization,which included phospholipids scramblase,aminophospholipid translocases and ATP-dependent floppase.