DeLaney R G, Fishman A P
Am J Physiol. 1977 Nov;233(5):R181-7. doi: 10.1152/ajpregu.1977.233.5.R181.
During aestivation, the breathing pattern of the lungfish changed from the usual aquatic pattern of a single breath followed by prolonged apnea to the pattern of alternating tachypnea and apnea that characterizes Cheyne-Stokes breathing. As aestivation continued, the number of breaths per tachypneic period increased gradually to reach a steady level at about the 3rd mo. During the bouts of tachypnea, minute ventilation increased because of the increase in respiratory frequency even though tidal volumes decreased. Ventilation of the lungs during aestivation appeared to involve the same mechanism as during life in water, i.e., a buccal force pump. The breathing cycle began with the aspiration of air into the mouth as the buccal cavity enlarged. Lung deflation then occurred abetted by contraction of the abdominal muscles. Lung inflation followed and involved the "swallowing" of air form the posterior buccal region into the lungs. Cycles of deflation and partial inflation of the lungs were repeated 8-40 times (tachypneic period). At the end of the tachypneic cycle, after the last deflation, a series of larger buccal force-pump maneuvers reinflated the lungs before the start of the apneic period.
在夏眠期间，肺鱼的呼吸模式从通常的单次呼吸后长时间呼吸暂停的水生模式转变为以潮式呼吸为特征的呼吸急促与呼吸暂停交替的模式。随着夏眠的持续，每个呼吸急促期的呼吸次数逐渐增加，在大约第3个月时达到稳定水平。在呼吸急促发作期间，尽管潮气量减少，但由于呼吸频率增加，每分通气量仍增加。夏眠期间肺部的通气似乎涉及与在水中生活时相同的机制，即口腔压力泵。呼吸周期始于随着口腔腔扩大空气被吸入口腔。随后，腹部肌肉收缩促使肺部排气。接着肺部充气，包括从口腔后部区域“吞咽”空气进入肺部。肺部排气和部分充气的周期重复8 - 40次（呼吸急促期）。在呼吸急促周期结束时，最后一次排气后，在呼吸暂停期开始前，一系列较大的口腔压力泵动作使肺部再次充气。
