Hutchison V H, Miller K
Respir Physiol. 1979 Sep;38(1):93-103. doi: 10.1016/0034-5687(79)90009-4.
In conditions of declining water PO2, Xenopus obtains the majority of resting oxygen needs from lung breathing at 15 degrees and 25 degrees C. The critical oxygen tension was 120 +/- 9 mm Hg at 15 degrees C, and 90 +/- 10 mm Hg at 25 degrees C. During 30 min stimulation of activity to complete exhaustion at 15 degrees C, frogs exhibited an aerobic capacity of 1.7 microliter O2.g-1.h-1 and accumulated 2.22 mg lactate . g-1. Following activity these animals exhibited an oxygen debt of 49.2 microliter O2.g-1. At 25 degrees C, Xenopus had an aerobic capacity of 16.1 microliter O2.g-1 and accumulated 1.94 mg lactate . g-1. Following activity, 25 degrees C frogs exhibited an oxygen debt of 261.9 microliter O2.g-1. Thus at 15 degrees C, Xenopus acquires 85% of the ATP used during a bout of sustained exhaustive activity from anaerobic sources, and 98% at 25 degrees C. Recovery from exhaustive activity was complete after 5 h at 25 degrees C and 9 h at 15 degrees C. Comparison of these data with those of other amphibians stimulated to sustained activity suggests that aquatic amphibians can tolerate a larger lactate load than can terrestrial forms.
在水体氧分压下降的情况下，非洲爪蟾在15摄氏度和25摄氏度时，通过肺呼吸获取大部分静息时的氧气需求。15摄氏度时的临界氧张力为120±9毫米汞柱，25摄氏度时为90±10毫米汞柱。在15摄氏度下，将青蛙的活动刺激30分钟直至完全疲惫，青蛙表现出的有氧能力为1.7微升氧气·克⁻¹·小时⁻¹，累积了2.22毫克乳酸·克⁻¹。活动后，这些动物表现出的氧债为49.2微升氧气·克⁻¹。在25摄氏度时，非洲爪蟾的有氧能力为16.1微升氧气·克⁻¹，累积了1.94毫克乳酸·克⁻¹。活动后，25摄氏度的青蛙表现出的氧债为261.9微升氧气·克⁻¹。因此，在15摄氏度时，非洲爪蟾在一轮持续的力竭性活动中，85%的ATP来自无氧来源，在25摄氏度时这一比例为98%。在25摄氏度下5小时后以及在15摄氏度下9小时后，力竭性活动后的恢复完成。将这些数据与其他被刺激进行持续活动的两栖动物的数据进行比较表明，水生两栖动物比陆生两栖动物能耐受更大的乳酸负荷。
