红细胞摄取氧气并释放二氧化碳
中文名称
通路描述
红细胞在肺毛细血管中循环必须在其在肺组织中的短暂 (0.5-1 秒) 转运时间内交换二氧化碳 (CO2) 和氧气 (O2)。CO2 以碳酸结合形式与血红蛋白的 N 端结合，以及质子 (H+) 与血红蛋白中的组氨酸残基结合，当血红蛋白 (HbA) 结合 O2 时释放。血浆中的碳酸氢根 (HCO3-) 通过带 3 阴离子交换体 (AE1, SLC4A1) 被红细胞摄取，并与 H+ 结合由碳酸酐酶 I 和 II (CA1/CA2) 生成水和 CO2 (由 Esbaugh 和 Tufts 2006 综述)。CO2 通过 AQP1 和 RhAG 被动地从红细胞转运出去。血浆中的 HCO3- 也由存在于肺毛细血管内皮细胞上的细胞外碳酸酐酶 IV (CA4) 直接脱水。
英文描述
Erythrocytes take up oxygen and release carbon dioxide Erythrocytes circulating through the capillaries of the lung must exchange carbon dioxide (CO2) for oxygen (O2) during their short (0.5-1 sec.) transit time in pulmonary tissue (Reviewed in Jensen 2004, Esbaugh and Tufts 2006, Boron 2010). CO2 bound as carbamate to the N-terminus of hemoglobin and protons (H+) bound to histidine residues in hemoglobin are released as hemoglobin (HbA) binds O2. Bicarbonate (HCO3-) present in plasma is taken up by erythrocytes via the band3 anion exchanger (AE1, SLC4A1) and combined with H+ by carbonic anhydrases I and II (CA1/CA2) to yield water and CO2 (Reviewed by Esbaugh and Tufts 2006). CO2 is passively transported out of the erythrocyte by AQP1 and RhAG. HCO3- in plasma is also directly dehydrated by extracellular carbonic anhydrase IV (CA4) present on endothelial cells lining the capillaries in the lung.
所含基因
8 个基因