Department of Environment and Agriculture, Curtin University, PO Box U1987, Bentley, WA, 6845, Australia.
J Comp Physiol B. 2011 Jul;181(5):657-65. doi: 10.1007/s00360-011-0551-9. Epub 2011 Jan 23.
Duration and start time of respirometry experiments have significant effects on the measurement of basal values for several commonly measured physiological variables (metabolic rate, evaporative water loss and body temperature). A longer measurement duration reduced values for all variables for all start times, and this was an effect of reduced animal activity rather than random sampling. However, there was also an effect of circadian rhythm on the timing of minimal physiological values. Experiment start time had a significant effect on time taken to reach minimal values for all variables, ranging from 0400 hours ± 38 min (body temperature, start time 2300 hours) to 0854 hours ± 52 min (evaporative water loss, start time 1700 hours). It also influenced the time of day that minimal values were obtained, ranging from 2224 hours ± 40 min (carbon dioxide production, start time 1500 hours) to 0600 hours ± 57 min (oxygen consumption, start time 2300 hours), and the minimum values measured. Consequently, both the measurement duration and the experiment start time should be considered in experimental design to account for both a handling and a circadian effect on the animal's physiology. We suggest that experiments to measure standard physiological variables for small diurnal birds should commence between 1700 and 2100 hours, and measurement duration should be at least 9 h.
呼吸代谢测量实验的持续时间和起始时间对几种常用生理变量（代谢率、蒸发失水和体温）的基础值测量有显著影响。较长的测量时间会降低所有变量在所有起始时间的数值，这是动物活动减少的影响，而不是随机抽样的影响。然而，生理最小值的时间也受到昼夜节律的影响。实验起始时间对所有变量达到最小值所需的时间有显著影响，范围从 0400 小时 ± 38 分钟（体温，起始时间 2300 小时）到 0854 小时 ± 52 分钟（蒸发失水，起始时间 1700 小时）。它还影响获得最小值的时间，范围从 2224 小时 ± 40 分钟（二氧化碳产生，起始时间 1500 小时）到 0600 小时 ± 57 分钟（耗氧量，起始时间 2300 小时）和测量的最小值。因此，在实验设计中应考虑测量持续时间和实验起始时间，以考虑动物生理的处理和昼夜节律影响。我们建议，测量小型昼行鸟类标准生理变量的实验应在 1700 至 2100 小时之间开始，测量时间应至少为 9 小时。
