缺铁幼大鼠红细胞膜阴离子交换蛋白的DIDS通透抑制效应变化

为了探讨缺铁性贫血（ＩＤＡ）红细胞膜阴离子交换蛋白（带３蛋白）的阴离子转运功能下降病变机理，运用生物膜离子通透研究方法，测定经Ｐｅｒｃｏｌｌ密度梯度分离的ＩＤＡ幼大鼠不同年龄红细胞的阴离子（ＮＯ２、Ｃ１-）通透速率；采用阴离子转运特异抑制剂ＤＩＤＳ和带３膜外侧阴离子转运肽段特异抗体作“探针”，观察其对缺铁红细胞的阴离子通透抑制效应。实验显示，ＤＩＤＳ抗体对ＩＤＡ红细胞的ＣＩ-通透抑制低于对照。进一步分析发现，分布于Ｐｅｒｃｏｌｌ上层的年青缺铁红细胞ＮＯ２一通透时间（Ｔｓ）明显延长，ＤＩＤＳ对该层红细胞的通透抑制率显著下降；中、老年红细胞各参数变化无统计学显著意义。结果提示，缺铁红细胞膜外侧带３蛋白的阴离子结合位点发生病变；病变以新生红细胞表现严重；导致铁红细胞阴离子通透功能改变的带３分子结构变化可能发生在骨髓缺铁红细胞合成期。

THE INHIBITION OF DIDS ON ANION EXCHANGER OF ERYTHROCYTE OF GROWING RAT WITH IRON DIFICIENT ANEMIA

To explore the mechanism of the decrease of the anion transport function of band 3 protein in erythrocyte membrane in iron deficient anemia (IDA),anion (NO, and CI--transportrate across erythrocyte membrane in growing rats with iron deficient anemia was measuredbe fore and after separation of the erythrocyts according to age on a discontinuous Percolldensity gradient. The inhibition of the anion transport by the stilbene anion exchange inhibitor DIDS(4, 4'--diisothiocyanostilbene--2, 2'--disulfonic acid)and the antibody to the transmemblane domain related to the anion transport function of band 3 protein was investigated.It was fornd that the inhibited effect of both the DIDS and anti--band 3 antibody on the Cltransport of the unseparated erythocytes was lower in IDA group than in control group. Further study with the erythcytes separated by Percoll showed that the anion (NO, )transporttime was markedly prolonged and the efficiency of DIDS to inhibit the anion transport significantly weakened in only the young--aged iron--deficient cells, neither middle--nor old--aged.The results demonstrate that there exist the abnormalities, the most severe in new--bornyoung red cells, in the anion binding sites of bane 3 protein on the extramembrane of IDAerythrocytes. It is Suggested that changes of band 3 molecular construction resultion in decreased anion transport activity may occur at the stage of iron--deficient erythropoiesis in bonemarrow.