Suzuki S, Sugita M, Noda M, Tsubochi H, Fujimura S
Department of Thoracic Surgery, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
Respir Physiol. 1999 May 3;115(3):325-32. doi: 10.1016/s0034-5687(99)00009-2.
We evaluated the effects of intraalveolar oxygen concentration on alveolar fluid absorption and metabolism in isolated rat lungs. Alveolar fluid absorption was determined by measuring increase in albumin concentration in the instillate solution during 2 h of incubation. Oxidative phosphorylation was assessed by gas analysis of the solution. Glycolysis was assessed by determining glucose escape and lactate release in the solution. We found that alveolar fluid absorption did not change under hyperoxic and hypoxic experimental environments (range 100-10% oxygen). Glycolysis was reduced under hyperoxia and stimulated under hypoxia, however, lung ATP content did not change. When oxidative phosphorylation was inhibited by NaCN, both alveolar fluid absorption and lung ATP content were reduced. Our data indicate that isolated rat lungs maintain optimal energy production for alveolar fluid absorption by stimulating glycolysis, even though glycolysis alone is not enough. We conclude that alveolar fluid absorption determined in isolated rat lungs is not influenced by intraalveolar oxygen concentration in the range above 10% oxygen.
我们评估了肺泡内氧浓度对离体大鼠肺脏肺泡液体吸收及代谢的影响。通过测量孵育2小时期间灌洗液中白蛋白浓度的增加来确定肺泡液体吸收情况。通过对溶液进行气体分析来评估氧化磷酸化。通过测定溶液中葡萄糖逸出量和乳酸释放量来评估糖酵解。我们发现，在高氧和低氧实验环境（氧浓度范围为100% - 10%）下，肺泡液体吸收没有变化。高氧时糖酵解减少，低氧时糖酵解受到刺激，然而，肺脏ATP含量没有变化。当用氰化钠抑制氧化磷酸化时，肺泡液体吸收和肺脏ATP含量均降低。我们的数据表明，离体大鼠肺脏通过刺激糖酵解来维持肺泡液体吸收的最佳能量产生，尽管仅靠糖酵解是不够的。我们得出结论，在氧浓度高于10%的范围内，离体大鼠肺脏中所测定的肺泡液体吸收不受肺泡内氧浓度的影响。
