Oxygen tension modulates Ca2+ response to flow stimulus in endothelial cells exposed to hydrostatic pressure.
Oxygen tension modulates Ca2+ response to flow stimulus in endothelial cells exposed to hydrostatic pressure.
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DOI：
10.3233/thc-2003-11406
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发表时间：
2003-11
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影响因子：
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通讯作者：
T. Ohashi;N. Sakamoto;Akiyo Iwao;Masaaki Sato
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文献类型：
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作者：
T. Ohashi;N. Sakamoto;Akiyo Iwao;Masaaki Sato
研究了氧气张力和静水压力对内皮细胞内钙离子[Ca 2 +]i对流动刺激的反应的影响。将培养的牛主动脉内皮细胞（BAEC）暴露于在低氧气体张力下的100 mmHg的流体静压，随后经受20达因/cm 2的流体剪切应力的1分钟机械刺激。使用荧光指示剂钙绿色-1测量BAEC中的[Ca 2 +]i响应。低氧张力的最大强度显著低于正常氧张力，这提供了低氧张力向下调节细胞功能的证据。此外，静水压力预负荷也降低了[Ca 2 +]i的增加。这些结果表明，在静脉系统中，氧分压和静水压力低于动脉系统，BAEC可能是不敏感的流体流量。单独的观察结果表明，低氧张力并没有显着影响细胞形态。与此相反，BAECs暴露于静水压力表现出显着的伸长率，没有主导方向和F-肌动蛋白丝分布重排，表明位于中心的厚应力纤维。为了更好地理解内皮细胞的生理，这是非常重要的，以阐明氧气的压力和机械环境对内皮细胞的反应的影响。
The effects of oxygen gas tensions and hydrostatic pressure on intracellular calcium, [Ca2+]i, response to a flow stimulus in endothelial cells were investigated. Cultured bovine aortic endothelial cells (BAECs) were exposed to a hydrostatic pressure of 100 mmHg under low oxygen gas tensions and were subsequently subjected to a 1 minute mechanical stimulation of fluid shear stress of 20 dynes/cm2. The [Ca2+]i response in BAECs was measured using a fluorescent indicator, Calcium Green-1. The maximum intensity for low oxygen tension was significantly lower than that for normal oxygen tension, which provides evidence that low oxygen tension regulates cellular functions downward. Moreover, preloading of hydrostatic pressure also reduced the increases in [Ca2+]i. These results suggest that BAECs in venous system, where oxygen tension and hydrostatic pressure are lower than those in arterial system, may be less sensitive to fluid flow. A separate observation showed that low oxygen tension did not significantly affect the cell morphology. In contrast, BAECs exposed to hydrostatic pressure showed marked elongation with no predominant orientation and the F-actin filament distributions were rearranged, indicating centrally located thick stress fibers. For better understanding of endothelial cell physiology, it is very important to elucidate the effect of oxygen gas tensions together with mechanical environment on endothelial cell responses.