STIMULUS-RESPONSE CURVES FOR PULMONARY VASCULAR BED TO HYPOXIA AND HYPERCAPNIA
STIMULUS-RESPONSE CURVES FOR PULMONARY VASCULAR BED TO HYPOXIA AND HYPERCAPNIA
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DOI：
10.1113/jphysiol.1970.sp009271
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发表时间：
1970-01-01
影响因子：
5.5
通讯作者：
SHAW, JW
中科院分区：
文献类型：
--
作者：
BARER, GR;HOWARD, P;SHAW, JW
1.在麻醉开胸猫犬中，测量插入肺静脉回路的血流和气体张力，同时对低O2和高CO2混合气体引流的肺叶进行通风。低氧和高碳酸血症混合液均可导致肺叶血流量减少。获得了血流量与肺静脉血氧分压和二氧化碳分压的刺激反应曲线。低氧的曲线通常是渐近的；曲线在100torr以下变得陡峭，有时流量降至零。血流量每下降20托，猫平均减少15.7%，狗平均减少11.8%。对于高碳酸血症，起初是陡峭的，但在高PCO2值时趋于平稳；由于仅在有限的PCO2范围内观察到血管收缩，血流量最大减少了40%-60%。肺叶换气不足导致血流量减少。这主要归因于缺氧，尽管其他因素，如高碳酸血症，有时也可能起到作用。完全闭塞充满氧气的肺叶的支气管会导致血流分两个阶段下降。第一阶段可归因于PCO2的上升，第二阶段可归因于PO2.6的下降。结果证实了低氧是调节局部血流量与局部通气性有关的重要因素的假说。
1. In anaesthetized open‐chest cats and dogs, blood flow and gas tensions were measured in a circuit inserted into a pulmonary vein while ventilating the lobe which it drained with low O2and high CO2mixtures.2. Both hypoxic and hypercapnic mixtures caused a reduction in blood flow from the lobe.3. Stimulus—response curves relating blood flow to pulmonary venousPO2andPCO2were obtained. Those for hypoxia were usually asymptotic in shape; the curves became steep below 100 torr and flow sometimes fell to zero. The mean reduction in blood flow for every 20 torr fall inPO2was 15·7% in cats and 11·8% in dogs. Those for hypercapnia were steep at first but levelled out at highPCO2values; the maximum reduction in flow was 40–60% as vasoconstriction was only observed over a limitedPCO2range.4. Hypoventilation of the lobe led to a reduction in blood flow. This was mainly attributable to hypoxia though other factors such as hypercapnia may sometimes have contributed.5. Total occlusion of the bronchus of an O2‐filled lobe caused blood flow to fall in two phases. The first phase could be attributed to a rise inPCO2and the second to a fall inPO2.6. The results confirm the hypothesis that hypoxia is an important factor regulating local blood flow in relation to local ventilation.