Foëx P, Saner C A, Fordham R M, Roberts J G, Bennett M J
Bull Eur Physiopathol Respir. 1976 Mar-Apr;12(2):231-9.
The cardiovascular system of the anaesthetized dog has been used as an experimental model for studying the mechanisms of the haemodynamic responses to hypoxia. Together with aortic and left circumflex coronary artery blood flow (electromagnetic flow transducers), aortic and left ventricular pressures have been recorded and blood has been sampled from the aorta and the coronary sinus (PO2, PCO2, pH). During short periods of hypoxia an improvement of myocardial performance has been observed both before and after administration of a beta-adrenergic receptor blocker and a marked reduction of coronary sinus PCO2 has been noted. When hypoxia was caused by a mixture of nitrogen (95%) and CO2 (5%) an improvement of performance was observed only before administration of the beta-blocker. The slope of the relationship between PCSCO2 and cardiac performance was found to be similar before and after administration of the beta-blocker and also similar to that observed in studies of the response of the isolated heart muscle to acute hypocapnia. Besides beta-adrenergic receptor stimulation, a reduction of coronary sinus PCO2 (CO2 wash-out due to an increase of coronary blood flow) could be a factor contributing to the maintenance of myocardial performance in the face of hypoxia.
麻醉犬的心血管系统已被用作实验模型，用于研究对缺氧的血流动力学反应机制。连同主动脉和左旋冠状动脉血流量（电磁流量传感器）一起，记录了主动脉和左心室压力，并从主动脉和冠状窦采集了血液样本（PO2、PCO2、pH）。在短时间缺氧期间，在给予β-肾上腺素能受体阻滞剂之前和之后均观察到心肌性能有所改善，并且注意到冠状窦PCO2显著降低。当缺氧由氮气（95%）和二氧化碳（5%）的混合物引起时，仅在给予β-阻滞剂之前观察到性能有所改善。发现给予β-阻滞剂之前和之后，冠状窦PCO2与心脏性能之间关系的斜率相似，并且也与在离体心肌对急性低碳酸血症反应的研究中观察到的斜率相似。除了β-肾上腺素能受体刺激外，冠状窦PCO2的降低（由于冠状动脉血流量增加导致的二氧化碳清除）可能是在缺氧情况下维持心肌性能的一个因素。
