Nitric oxide generation in red blood cells induced by mechanical stress
Nitric oxide generation in red blood cells induced by mechanical stress
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DOI：
10.3233/ch-2010-1293
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发表时间：
2010-01-01
影响因子：
2.1
通讯作者：
Baskurt, Oguz K.
中科院分区：
文献类型：
--
作者：
Ulker, Pinar;Meiselman, Herbert J.;Baskurt, Oguz K.
以往的研究表明，红细胞（RBC）具有活性一氧化氮（NO）合成机制，其性质类似于内皮型一氧化氮合酶（eNOS）。这种红细胞NOS活性有助于从RBC输出NO。本研究探讨了切应力对红细胞悬液中NO浓度的影响。通过在10 cm H2O压力下过滤通过5 μ m直径的孔，使RBC暴露于剪切应力，产生类似于110 Pa的壁剪切应力。在通过微孔过滤之前和之后，使用电化学NO探针测量RBC悬浮液中的NO浓度。NO浓度被发现后，通过微孔的RBC悬浮液的单通道显着增加。NO浓度的增加取决于钙的存在，在1 mM钙的情况下为21.8 +/- 4.4 nM，在不添加钙的情况下为13.7 +/- 2.7 nM。包括钙螯合剂EDTA完全消除了这种增加。NO的增加也受到氧合水平的影响，在缺氧条件下更为明显。这些结果证实，红细胞NO生成机制可以通过将红细胞暴露于剪切应力来刺激，并且钙在这种刺激中起作用。
Previous reports have demonstrated that red blood cells (RBC) have an active nitric oxide (NO) synthesizing mechanism which has properties similar to endothelial nitric oxide synthase (eNOS). This red cell NOS activity contributes to the NO export from RBC. The present study explored the influence of shear stress applied to RBC on NO concentrations of cell suspensions. RBC were exposed to shear stress by filtration through 5 mu m diameter pores under 10 cm H2O pressure, generating a wall shear stress of similar to 110 Pa. NO concentration in the RBC suspensions were measured using electrochemical NO probes before and after filtration through the micropores. NO concentration was found to be significantly increased after a single passage of RBC suspensions through the micropores. The increment in NO concentration depended on the presence of calcium, being 21.8 +/- 4.4 nM with 1 mM calcium and 13.7 +/- 2.7 nM without added calcium. Including the calcium chelator EDTA completely abolished this increase. The increment of NO was also affected by the level of oxygenation, being more pronounced under hypoxic conditions. These results confirm that RBC NO generating mechanisms can be stimulated by exposing red cells to shear stress and that calcium plays a role in this stimulation.