Oonishi T, Sakashita K, Uyesaka N
Nippon Telegraph and Telephone Corporation, Medical Research Institute, Kanto Teishin Hospital, Tokyo, Japan.
Am J Physiol. 1997 Dec;273(6):C1828-34. doi: 10.1152/ajpcell.1997.273.6.C1828.
To investigate the mechanism of the regulation of human red blood cell deformability, we examined the deformability under mechanical stress. Washed human red blood cells were rapidly injected through a fine needle, and their filterability was measured using a nickel mesh filter. The decrease in filterability showed a V-shaped curve depending on the extracellular Ca2+ concentration; the maximum decrease was achieved at approximately 50 muM. The decreased filterability was accompanied by no change in cell morphology and cell volume, indicating that the decrease in filterability can be ascribed to alterations of the membrane properties. Ca2+ entry blockers (nifedipine and felodipine) inhibited the impairment of filterability under mechanical stress. Prostaglandins E1 and E2, epinephrine, and pentoxifylline, which are thought to modulate the intracellular adenosine 3',5'-cyclic monophosphate (cAMP) level of red blood cells, improved or worsened the impaired filterability according to their expected actions on the cAMP level of the cells. These results strongly suggest that the membrane properties regulating red blood cell deformability are affected by the signal transduction system, including Ca(2+)-dependent and cAMP-mediated signaling pathways.
为了研究人类红细胞变形性的调节机制，我们检测了机械应力下的变形性。将洗涤后的人类红细胞通过细针快速注入，并使用镍网过滤器测量其过滤性。过滤性的降低呈现出一条依赖于细胞外Ca2+浓度的V形曲线；在约50μM时达到最大降低值。过滤性降低的同时细胞形态和细胞体积没有变化，这表明过滤性的降低可归因于膜特性的改变。Ca2+通道阻滞剂（硝苯地平和非洛地平）抑制了机械应力下过滤性的损伤。前列腺素E1和E2、肾上腺素和己酮可可碱，这些物质被认为可调节红细胞内3',5'-环磷酸腺苷（cAMP）水平，根据它们对细胞cAMP水平的预期作用，改善或加剧了受损的过滤性。这些结果强烈表明，调节红细胞变形性的膜特性受信号转导系统影响，包括Ca(2+)依赖性和cAMP介导的信号通路。
