Dauger S, Nsegbe E, Vardon G, Gaultier C, Gallego J
Laboratoire de Neurologie et Physiologie du Développement, Hôpital Robert-Debré, Paris, France.
Respir Physiol. 1998 May;112(2):215-25. doi: 10.1016/s0034-5687(98)00027-9.
The aim of this experiment was to determine whether ventilatory measurements in adult restrained mice provide a valid assessment of chemosensitivity. We used whole-body plethysmography to compare breathing patterns in eight restrained and eight unrestrained outbred Swiss mice during air breathing, hypercapnia, and hypoxia. The mice in the restrained group were each placed in a loosely restraining wire-mesh cage. The unrestrained mice could move freely inside the plethysmograph. All the mice received three hypercapnic stimuli (8.5% CO2) and three hypoxic isocapnic stimuli (10% O2, 3.5% CO2). As compared to unrestrained mice, restrained mice had significantly lower breath durations (TT, 445+/-110 ms vs. 323+/-32 ms) and higher ventilation (VE) levels (15.7+/-2.6 microl/(sec x g) vs. 22.2+/-4.5 microl/(sec x g)), whereas no difference was observed for tidal volume (VT). The increases in frequency and ventilation from baseline to hypercapnia were not significantly different in restrained and unrestrained mice. The VE response to hypoxia was marginally higher in restrained mice. We conclude that chemosensitivity to hypercapnia, and to a lesser extent to hypoxia, can be measured in restrained adult mice, but that the baseline breathing pattern cannot.
本实验的目的是确定对成年束缚小鼠进行通气测量是否能有效评估化学感受性。我们使用全身体积描记法比较了八只束缚状态和八只自由活动的远交系瑞士小鼠在空气呼吸、高碳酸血症和低氧血症期间的呼吸模式。束缚组的小鼠分别被放置在一个宽松束缚的金属丝网笼中。自由活动的小鼠可以在体积描记器内自由活动。所有小鼠均接受了三次高碳酸血症刺激（8.5%二氧化碳）和三次低氧等碳酸血症刺激（10%氧气，3.5%二氧化碳）。与自由活动的小鼠相比，束缚小鼠的呼吸持续时间显著缩短（吸气时间，445±110毫秒对323±32毫秒），通气（VE）水平更高（15.7±2.6微升/（秒×克）对22.2±4.5微升/（秒×克）），而潮气量（VT）没有差异。束缚小鼠和自由活动小鼠从基线到高碳酸血症时频率和通气的增加没有显著差异。束缚小鼠对低氧的VE反应略高。我们得出结论，对成年束缚小鼠可以测量其对高碳酸血症的化学感受性，对低氧的化学感受性程度稍低，但无法测量其基线呼吸模式。
