镰状红细胞中钙泵和钙-钙交换的进行性抑制。

Progressive inhibition of the Ca pump and Ca:Ca exchange in sickle red cells.

作者信息

Bookchin R M, Lew V L

出版信息

Nature. 1980 Apr 10;284(5756):561-3. doi: 10.1038/284561a0.

Abstract

Sickle cell anaemia red cells (SS) were reported to have a high Ca content and an increased Ca uptake on deoxygenation, but their Ca-pump activity was described as normal. This seemed puzzling because the saturated Ca-extrusion rate of the normal, high Ca-affinity Ca pump is about 10 mmol per 1 cells per h (refs 3, 4) and the highest sickling-induced Ca influx reported in SS cells and observed in ATP-depleted sickle-trait (SA) red cells never exceeded 0.2 mmol per 1 cells per h. Normal pump performance is, therefore, incompatible with Ca accumulation unless SS cells have abnormally high Ca-binding capacity. We provide here evidence which suggests that SS cells have normal Ca-buffering capacity and probably genetically normal Ca pumps, but that the sickling process causes progressive Ca-pump failure and a marked reduction in Ca:Ca exchange.

摘要

据报道，镰状细胞贫血红细胞（SS）的钙含量很高，脱氧时钙摄取增加，但其钙泵活性被描述为正常。这似乎令人费解，因为正常的高钙亲和力钙泵的饱和钙外排率约为每1个细胞每小时10 mmol（参考文献3、4），而在SS细胞中报道的、在ATP耗尽的镰状性状（SA）红细胞中观察到的最高镰变诱导钙内流从未超过每1个细胞每小时0.2 mmol。因此，除非SS细胞具有异常高的钙结合能力，否则正常的泵功能与钙积累是不相容的。我们在此提供的证据表明，SS细胞具有正常的钙缓冲能力，可能钙泵基因也正常，但镰变过程会导致钙泵逐渐衰竭以及钙:钙交换显著减少。