Littlejohn A, Bowles F
Onderstepoort J Vet Res. 1981 Dec;48(4):239-49.
The haemoglobin concentration, the partial pressures of oxygen and carbon dioxide, the oxygen content and the pH were determined in the arterial and mixed venous blood of 5 normal and 3 horses with chronic obstructive pulmonary disease (COPD) at 3 stages of an exercise distance of 1200 m. Arterial and mixed venous samples were collected simultaneously by means of an automatic technique during the walk, trot and gallop at 0-100 m, at 500-600 m and at 1100-1200 m. The standard bicarbonate and the lactic and pyruvic acid concentrations were also determined in arterial and mixed venous blood. Highly significant changes in the mean values of PvO2. O2 content and delta a-vO2 content occurred during exercise in COPD subjects, and significant changes in PvO2 and delta a-vO2 content occurred during exercise in normal subjects. We concluded that COPD subjects compensated for respiratory dysfunction during exercise by extracting more oxygen from the blood than did normal horses. There was a highly significant correlation between the changes in standard bicarbonate and the changes in lactic acid concentration during exercise in both normal and COPD subjects. This led to the conclusion that lactic acid production was primarily, but not completely, responsible for the metabolic acidosis of exercise in horses.
在5匹正常马和3匹患有慢性阻塞性肺疾病（COPD）的马进行1200米运动距离的3个阶段中，测定了动脉血和混合静脉血中的血红蛋白浓度、氧分压和二氧化碳分压、氧含量以及pH值。在0至100米、500至600米和1100至1200米的步行、小跑和疾驰过程中，通过自动技术同时采集动脉血和混合静脉血样本。还测定了动脉血和混合静脉血中的标准碳酸氢盐以及乳酸和丙酮酸浓度。在COPD受试者运动期间，PvO2、O2含量和Δa-vO2含量的平均值发生了高度显著变化，而在正常受试者运动期间，PvO2和Δa-vO2含量发生了显著变化。我们得出结论，COPD受试者在运动期间通过从血液中提取比正常马更多的氧气来代偿呼吸功能障碍。在正常和COPD受试者运动期间，标准碳酸氢盐的变化与乳酸浓度的变化之间存在高度显著的相关性。由此得出结论，乳酸生成主要但并非完全是导致马运动性代谢性酸中毒的原因。
