Hughson R L
Eur J Appl Physiol Occup Physiol. 1980;45(2-3):103-8. doi: 10.1007/BF00421317.
A CO2 rebreathing technique was used to assess possible changes in the ventilatory response to CO2 in rats following a 14-week swim training program. Over the final 9 weeks, the rats swam 1 hr per day with a weight of 2.5% of the body weight attached to the tail. Ventilation was measured by a barometric method in awake, restrained rats in a total body plethysmography at CO2 concentrations of 0, 2, 4, 6, and 8%, with an initial O2 concentration of approximately 100%. Ventilation increased in the trained rats with increasing CO2 from 775ml . min-1 . kg-1 at 0% CO2 to 1,387 ml . min-1 . kg-1 at 8% CO2. This increase was a consequence of a 34% increase in tidal volume and a 32% increase in breathing frequency. In comparison with a group of sedentary control rats, there was a significantly higher ventilation and tidal volume at 0% CO2; however, this difference disappeared with increasing levels of CO2. A significantly lower resting heart rate was observed in the exercised (296 +/- 44 beats . min-1, mean +/- SD) compared to the sedentary control rats 380 +/- 42). It was concluded that, while the normal training response of resting bradycardia was observed following this duration and intensity of training, endurance swimming had no significant effect on the ventilatory response to CO2 in the rat.
采用二氧化碳重复呼吸技术，评估大鼠经过14周游泳训练后对二氧化碳通气反应的可能变化。在最后9周，大鼠每天游泳1小时，尾巴上附着相当于体重2.5%的重物。在全身体积描记器中，通过气压法在清醒、受约束的大鼠中测量通气，二氧化碳浓度分别为0%、2%、4%、6%和8%，初始氧气浓度约为100%。训练组大鼠的通气量随着二氧化碳浓度的增加而增加，从0%二氧化碳时的775毫升·分钟-1·千克-1增加到8%二氧化碳时的1387毫升·分钟-1·千克-1。这种增加是潮气量增加34%和呼吸频率增加32%的结果。与一组久坐不动的对照大鼠相比，在0%二氧化碳时通气量和潮气量显著更高；然而，随着二氧化碳水平的增加，这种差异消失了。与久坐不动的对照大鼠（380±42次）相比，运动组大鼠的静息心率显著更低（296±44次·分钟-1，平均值±标准差）。得出的结论是，虽然经过此训练时长和强度后观察到了静息心动过缓的正常训练反应，但耐力游泳对大鼠对二氧化碳的通气反应没有显著影响。
