Kawakami Y, Kondo T, Kishi F, Asanuma Y, Murao M, Taniguchi N
Hokkaido Igaku Zasshi. 1978 Nov;52(6):327-35.
The activity and the isozyme B and C levels of red cell carbonic anhydrase was examined before and during CO2 inhalation in 18 patients with chronic respiratory failure. Carbonic anhydrase B and C levels did not change during 5 min breathing of high (8-9%) and low (3-5%) CO2 mixture. Carbonic anhydrase activity decreased in patients with combined hypercarbia (Paco2 greater than or equal to 45 mmHg) and hypoxemia (Pao2 less than or equal to 60 mmHg). This was accompanied by an increase in red cell K+ content, 2, 3-DPG and Hct/Hb. The activity did not change in patients with only hypoxemia. Carbonic anhydrase activity and plasma HCO-3 concentration were positively correlated (r = 0.4, P less than 0.05). A significant inverse correlation was also found between changes in red cell K+ content and those in carbonic anhydrase activity (r = - 0.42, P less than 0.05). These results indicate that 1), there is a dissociation between activity and isozyme levels in red cell carbonic anhydrase during the initial 5 min of CO2 breathing in patients with combined hypercarbia and hypoxemia, and 2), there seems a linkage exists between K+ movement across the red cell membrane and carbonic anhydrase activity.
对18例慢性呼吸衰竭患者在吸入二氧化碳之前及过程中检测了红细胞碳酸酐酶的活性以及同工酶B和C的水平。在呼吸高浓度（8 - 9%）和低浓度（3 - 5%）二氧化碳混合气5分钟期间，碳酸酐酶B和C的水平未发生变化。在合并高碳酸血症（动脉血二氧化碳分压大于或等于45 mmHg）和低氧血症（动脉血氧分压小于或等于60 mmHg）的患者中，碳酸酐酶活性降低。这伴随着红细胞钾离子含量、2,3 - 二磷酸甘油酸以及血细胞比容/血红蛋白的增加。仅患有低氧血症的患者中该活性未发生变化。碳酸酐酶活性与血浆碳酸氢根浓度呈正相关（r = 0.4，P < 0.05）。在红细胞钾离子含量变化与碳酸酐酶活性变化之间也发现了显著的负相关（r = - 0.42，P < 0.05）。这些结果表明，1），在合并高碳酸血症和低氧血症的患者中，在吸入二氧化碳的最初5分钟内，红细胞碳酸酐酶的活性与同工酶水平之间存在分离，并且2），钾离子跨红细胞膜的移动与碳酸酐酶活性之间似乎存在联系。
