Koizumi M
First Department of Medicine, School of Medicine, Hokkaido University, Sapporo, Japan.
Nihon Kyobu Shikkan Gakkai Zasshi. 1991 May;29(5):547-53.
The measurement of the oxyhemoglobin dissociation curve (ODC) and 2,3-diphosphoglycerate (2,3-DPG) in patients with chronic hypoxemia is important from the view point of tissue oxygenation. However, there have been no consistent results that explain the relation among chronic hypoxemia, 2,3-DPG and P50, which is oxygen pressure at an oxygen saturation of 50 percent. The aim of this study is to clarify what factors affect P50 and 2,3-DPG. 1) Patients with chronic hypoxemia, who showed PaO2 less than 60 Torr, had significantly higher P50 than normal subjects. 2) The concentration of Hb showed significant negative correlation with both P50 and 2,3-DPG. 3) Arterial blood pH showed significant positive correlation with both P50 and 2,3-DPG. 4) In a group with normal levels of Hb and pH, there was significant negative relationship between PaO2 and P50. 5) In a group with normal levels of Hb and pH, there was significant positive relationship between PaCO2 and P50. 6) In a group with normal levels of Hb, pH and PaCO2, there was significant negative relationship between PaO2 and 2,3-DPG. In conclusion, P50 and 2,3-DPG are affected largely by Hb concentration or blood pH, with or without hypoxemia. However there is a mechanism by which P50 and 2,3-DPG are increased by hypoxemia itself in a group with normal levels of Hb, pH and PaCO2.
从组织氧合的角度来看，测量慢性低氧血症患者的氧合血红蛋白解离曲线（ODC）和2,3 - 二磷酸甘油酸（2,3 - DPG）非常重要。然而，关于慢性低氧血症、2,3 - DPG和P50（50%氧饱和度时的氧分压）之间的关系，尚未有一致的结果。本研究的目的是阐明哪些因素会影响P50和2,3 - DPG。1）慢性低氧血症患者，其动脉血氧分压（PaO2）低于60托，其P50显著高于正常受试者。2）血红蛋白（Hb）浓度与P50和2,3 - DPG均呈显著负相关。3）动脉血pH值与P50和2,3 - DPG均呈显著正相关。4）在Hb和pH水平正常的组中，PaO2与P50之间存在显著负相关。5）在Hb和pH水平正常的组中，PaCO2与P50之间存在显著正相关。6）在Hb、pH和PaCO2水平正常的组中，PaO2与2,3 - DPG之间存在显著负相关。总之，无论有无低氧血症，P50和2,3 - DPG在很大程度上受Hb浓度或血液pH值的影响。然而，在Hb、pH和PaCO2水平正常的组中，存在一种机制使得低氧血症本身会使P50和2,3 - DPG升高。
