Ca2+ accumulation and loss by aberrant endocytic vesicles in sickle erythrocytes.
Ca2+ accumulation and loss by aberrant endocytic vesicles in sickle erythrocytes.
复制标题
镰状红细胞中异常内吞囊泡的 Ca2 积累和损失。
DOI：
10.1002/jcp.1041520102
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发表时间：
1992
影响因子：
5.6
通讯作者：
Schlegel,RA
中科院分区：
文献类型：
--
作者：
Williamson,P;Puchulu,E;Penniston,JT;Westerman,MP;Schlegel,RA
镰状细胞含有积累Ca 2+的内部囊泡。如图所示，包封囊泡的膜含有质膜Ca 2 +-ATP酶或Ca 2+泵，如通过针对蛋白质的抗体染色所判断的。此外，含有这种囊泡的细胞数量在脱氧后增加。这些发现有力地证明了囊泡是通过质膜的内吞作用产生的，并解释了它们是如何积累Ca 2+的。当镰状细胞耗尽ATP时，Ca 2+从囊泡中丢失，如通过Ca 2 +/膜探针金霉素（CTC）染色的消失所判断的，而没有相应的抗体染色的丢失。钙通道阻滞剂尼群地平可抑制这种钙丢失。这些结果表明，囊泡膜允许钙离子通过尼群地平敏感途径向外通过，这可以通过囊泡膜的钙离子泵的内向活性来克服。如果是这样的话，囊泡所含的Ca 2+与镰状红细胞的细胞质处于动态平衡。© 1992 Wiley利斯公司
Sickle cells contain internal vesicles which accumulate Ca2+. As shown here, the membrane enclosing the vesicles contains the plasma membrane Ca2+‐ATPase, or Ca2+pump, as judged by staining with an antibody directed against the protein. Moreover, the number of cells containing such vesicles increases upon deoxygenation. These findings argue strongly that the vesicles arise by endocytosis from the plasma membrane, and explain how they accumulate Ca2+. When sickle cells are depleted of ATP Ca2+is lost from the vesicles, as judged by the disappearance of staining with the Ca2+/membrane probe chlortetracycline (CTC), without a corresponding loss of antibody staining. This loss of Ca2+can be inhibited by nitrendipine, a Ca2+channel blocker. These results suggest that the vesicle membrane allows outward passage of Ca2+by a nitrendipine‐sensitive pathway, which can be overcome by the inward‐directed activity of the Ca2+pump of the vesicle membrane. If so, the Ca2+which vesicles contain is in dynamic equilibrium with the cytoplasm of the sickle erythrocyte. © 1992 Wiley‐Liss, Inc.