Gai Xuefeng, Taki Kenji, Kato Hiroyuki, Nagaishi Hisayo
Department of Emergency Medicine, Saga Medical College, Saga, Japan.
J Lab Clin Med. 2003 Dec;142(6):414-20. doi: 10.1016/j.lab.2003.07.001.
We studied the effect on hemoglobin (Hb)-oxygen affinity induced by changes in carbonic anhydrase (CA) activity. Oxygen partial pressure at the 50% saturation of Hb (P(50)) in human blood was measured as CA activity was inhibited to varying degrees with acetazolamide (AZ; 100 and 200 microg/mL). Transient but significant change in P(50) was observed when AZ was administered and the CO(2) concentration was changed from 10% to 5%. Finally, the differences induced with AZ were attenuated when the blood sample was subjected to 4 hours of tonometry. The findings in this study could be accounted for by reduced velocity of pH changes caused by the inhibition of CA by AZ. We conclude that CA can change Hb's affinity for oxygen by controlling the movement of CO(2) gas between air and liquid compartments.
我们研究了碳酸酐酶（CA）活性变化对血红蛋白（Hb）与氧亲和力的影响。使用乙酰唑胺（AZ；100和200μg/mL）将人血中CA活性抑制至不同程度，同时测量Hb饱和度为50%时的氧分压（P(50)）。当给予AZ且二氧化碳浓度从10%变为5%时，观察到P(50)出现短暂但显著的变化。最后，当对血样进行4小时的眼压测量时，AZ诱导的差异减弱。本研究中的发现可以通过AZ抑制CA导致pH变化速度减慢来解释。我们得出结论，CA可通过控制二氧化碳气体在气液隔室之间的移动来改变Hb对氧的亲和力。
