Frans A, Turek Z, Yokota H, Kreuzer F
Pflugers Arch. 1979 May 15;380(1):35-9. doi: 10.1007/BF00582609.
The effect of variation of blood hydrogen ion concentration on arterial and mixed venous PO2, ideal alveolar-arterial O2 pressure difference (PAiO2--PaO2), venous admixture (Qs/Qt), arterio-alveolar CO2 pressure difference (a--A)DCO2, physiological dead space to tidal volume ratio (VD/VT), cardiac output (Qt) and mean pulmonary arterial pressure (PAP) has been studied. Arterial and mixed venous PO2 increased and (PAiO2--PaO2) decreased with increasing blood hydrogen ion concentration. No change in Qs/Qt, (a--A)DCO2, VD/VT, Qt and PAP was observed. The effect of hydrogen ion concentration on arterial and mixed venous PO2 and on (PAiO2--PaO2) is mainly due to a shift of the blood oxyhemoglobin dissociation curve (ODC), i.e. due to the Bohr effect. The upper part of the ODC is more flat in alkalosis (shift to the left) than in acidosis (shift to the right). Therefore the same end-capillary to arterial O2 content difference results in a greater (PAiO2--PaO2) in alkalosis than in acidosis. Any factor influencing the slope of the upper part of the ODC is expected to affect the arterial PO2 and the (PAiO2--PaO2) by this mechanism. Similarly any factor shifting the steep part of the ODC is expected to affect the PO2 of the mixed venous blood.
研究了血液氢离子浓度变化对动脉血氧分压（PO2）、混合静脉血氧分压、理想肺泡 - 动脉血氧分压差（PAiO2 - PaO2）、静脉血掺杂（Qs/Qt）、动脉 - 肺泡二氧化碳分压差（a - A）DCO2、生理死腔与潮气量比值（VD/VT）、心输出量（Qt）和平均肺动脉压（PAP）的影响。随着血液氢离子浓度升高，动脉血氧分压和混合静脉血氧分压升高，而（PAiO2 - PaO2）降低。未观察到Qs/Qt、（a - A）DCO2、VD/VT、Qt和PAP有变化。氢离子浓度对动脉血氧分压和混合静脉血氧分压以及对（PAiO2 - PaO2）的影响主要归因于血液氧合血红蛋白解离曲线（ODC）的移位，即由于波尔效应。碱中毒时（曲线左移）ODC的上部比酸中毒时（曲线右移）更平坦。因此，相同的毛细血管末端到动脉血氧含量差值在碱中毒时导致的（PAiO2 - PaO2）比酸中毒时更大。预计任何影响ODC上部斜率的因素都会通过这种机制影响动脉血氧分压和（PAiO2 - PaO2）。同样，预计任何使ODC陡峭部分移位的因素都会影响混合静脉血的血氧分压。
