Gonzalez N C, Clancy R L, Wagner P D
Department of Physiology, University of Kansas Medical Center, Kansas City 66160-7401.
J Appl Physiol (1985). 1993 Oct;75(4):1608-14. doi: 10.1152/jappl.1993.75.4.1608.
The effect of acclimation to hypoxia on maximal O2 uptake (VO2max), maximal cardiac output (Qmax), and arteriovenous O2 concentration difference (a-vCO2) was studied in male Sprague-Dawley rats acclimated for 3 wk to a barometric pressure of approximately 380 Torr (A rats). Nonacclimated control animals were pair-fed littermates maintained at an ambient barometric pressure of approximately 740 Torr (NA rats). Both A and NA rats exercised maximally on a treadmill with inspired PO2 maintained at either approximately 72 or 145 Torr. Arterial blood O2 concentration was significantly higher in A than in NA rats (16.0 +/- 0.6 vs. 12.4 +/- 0.3 ml/dl in hypoxia and 28.4 +/- 1.5 vs. 20.1 +/- 0.9 ml/dl in normoxia, respectively; both P < 0.05). During hypoxic exercise VO2max was slightly but significantly higher in A than in NA subjects (55.3 +/- 1.3 vs. 48.8 +/- 1.1 ml STPD.min-1 x kg-1; P < 0.05). In hypoxia a-vCO2 was 16.6 +/- 0.6 and 12.4 +/- 0.4 ml/dl and Qmax was 401 +/- 17 and 489 +/- 9 ml.min-1 x kg-1 in A and NA subjects, respectively (both P < 0.05). A rats showed both lower maximal heart rate and lower maximal stroke volume during hypoxic exercise. In normoxia there was no significant difference in VO2max between A and NA rats (71.8 +/- 2.7 vs. 73.9 +/- 3.1 ml.min-1 x kg-1). As with hypoxia, in normoxia a-vCO2 was significantly higher and Qmax was significantly lower in A than in NA animals.(ABSTRACT TRUNCATED AT 250 WORDS)
研究了适应低氧环境对雄性斯普拉格-道利大鼠最大摄氧量（VO2max）、最大心输出量（Qmax）和动静脉氧浓度差（a-vCO2）的影响。将雄性斯普拉格-道利大鼠在约380托的气压下适应3周（A组大鼠）。未适应的对照动物为同窝配对饲养的大鼠，维持在约740托的环境气压下（NA组大鼠）。A组和NA组大鼠均在跑步机上进行最大运动，吸入氧分压维持在约72或145托。A组大鼠的动脉血氧浓度显著高于NA组大鼠（低氧时分别为16.0±0.6 vs. 12.4±0.3 ml/dl，常氧时分别为28.4±1.5 vs. 20.1±0.9 ml/dl；P均<0.05）。在低氧运动期间，A组大鼠的VO2max略高于但显著高于NA组大鼠（55.3±1.3 vs. 48.8±1.1 ml STPD·min-1·kg-1；P<0.05）。在低氧环境下，A组和NA组大鼠的a-vCO2分别为16.6±0.6和12.4±0.4 ml/dl，Qmax分别为401±17和489±9 ml·min-1·kg-1（P均<0.05）。A组大鼠在低氧运动期间的最大心率和最大每搏输出量均较低。在常氧环境下，A组和NA组大鼠的VO2max无显著差异（71.8±2.7 vs. 73.9±3.1 ml·min-1·kg-1）。与低氧环境时一样，在常氧环境下，A组大鼠的a-vCO2显著高于NA组大鼠，Qmax显著低于NA组大鼠。（摘要截短至250字）
