急性低压低氧大鼠氧比传导特征的实验研究

单位氧耗量氧比传导，简称氧比传导（ＭＯ２－ＳＣ）是新近提出的一项综合评价机体低氧生理性适应水平高低的客观指标。本实验于低压舱内模拟高原低压性低氧条件（相当于６０００ｍ海拔高度），研究了大量气体交换系统ＭＯ２－ＳＣ的适应特征及规律。结果发现，低氧条件下，从吸入气（Ｉ）至肺泡气（Ａ）（Ｉ→Ａ）、Ａ至脉动血（ａ）（Ａ→ａ）、ａ至混合静脉血（ｖ↑－）（ａ→ｖ↑－）及Ｉ→ｖ↑－间氧分压差明显减小（Ｐ〈０．０

MO_2-specific conductances in rat during acute hypobaric hypoxia

The MO_2-specific conductances(MO_2-SC)at four different levels,i.e.,inspired air to alveolar gas( I-A),A to arterial blood(A-a),a to mixed venous blood(a--v)and I to -v(I--v)in 12 SD rats under acute hypobaric hypoxia(simulate highaltitude 6,000m),It was observed that the oxygen partial pressure(PO_2)of four stepsfrom I to v remarkably decreased,but the MO_2-SC of each step incresed very much,especially at A to a step.These adaptive changes to hypoxia were probably owing to thestrong ventilation response,high lung diffusing capacity,lower arterial-venous shunt andhomogeneity in the distribution of alveolar ventilation and blood perfusion,etc. Theresults showed that the increased MO_2-SC seen during hypoxia implied a high transportoxygen capacity to tissued and a lower altitude to stay.We considered that the MO_2-SCwould be a good comprehensive indices to evaluate the organism adaptability to altitudehypoxia.