Emery C J, Sloan P J, Mohammed F H, Barer G R
Bull Eur Physiopathol Respir. 1977 Nov-Dec;13(6):763-76.
Two opposing actions of CO2 on pulmonary vessels, vasoconstriction and vasodilatation, were studied in dogs, cats, ferrets and rats using isolated lungs or a lobe of lung in vivo. Both preparations were perfused at a constant flow rate so that changes in inflow pressure at constant outflow pressure represented changes in vascular resistance. Lungs were ventilated with 5-15 percent CO2 during hypoxic vasoconstriction in order to permit demonstration of dilatation and because the two stimuli frequently concur. During hypoxia CO2 caused further constriction, dilatation or a biphasic response. Only constriction occurred in dogs and only dilatation in rats. Constriction predominated in cats but dilatation sometimes occurred in later tests in isolated lungs and after a carbonic anhydrase inhibitor. All three responses were seen in ferrets. The type of response did not depend on CO2 concentration. In rats dilatation turned to constriction after beta-adrenoreceptor blocking drugs. The vessels affected by dilatation could not be determined. Thus CO2 can enhance or diminish the action of hypoxia but the circumstances determining one or other action are not resolved.
利用离体肺或活体肺叶，在犬、猫、雪貂和大鼠身上研究了二氧化碳对肺血管的两种相反作用，即血管收缩和血管舒张。两种标本均以恒定流速灌注，因此在恒定流出压力下流入压力的变化代表血管阻力的变化。在低氧性血管收缩期间，用5% - 15%的二氧化碳对肺进行通气，以便能够证明血管舒张，因为这两种刺激常常同时出现。在低氧期间，二氧化碳会导致进一步的收缩、舒张或双相反应。犬只出现收缩，大鼠只出现舒张。猫以收缩为主，但在离体肺的后续试验中以及使用碳酸酐酶抑制剂后，有时会出现舒张。雪貂身上则出现了所有三种反应。反应类型并不取决于二氧化碳浓度。在大鼠中，β - 肾上腺素能受体阻断药物使用后，舒张转变为收缩。受舒张影响的血管无法确定。因此，二氧化碳可以增强或减弱低氧的作用，但决定这两种作用的具体情况尚未明确。
