Anestis Stephanie Firos, Bribiescas Richard G
Reproductive Ecology Laboratory, Yale University, New Haven, CT, 06520-8277, USA.
Horm Behav. 2004 Mar;45(3):209-13. doi: 10.1016/j.yhbeh.2003.09.015.
Behavioral endocrinologists are aware that many hormones exhibit a diurnal rhythm, and attempt to correct for this pattern by collecting physiological samples only during specified time windows of varying lengths. In studies utilizing urinary measures of hormone levels, this window often spans 2 h or longer. In this study, we compared chimpanzee urinary cortisol levels in sample pairs collected within 1 h of each other in an attempt to validate the use of a time window for sample collection. Chimpanzees were housed at the University of Louisiana New Iberia Research Center and trained to urinate into a paper cup on command; a total of 41 sample pairs were included in this analysis. We found that mean cortisol levels in the two sets of samples, collected within 1 h or less of each other, were significantly different; the mean cortisol level of the first set of samples was significantly higher than that of the second set. This hormone's diurnal pattern of secretion accounts for this significant decrease over a very short time period. We conclude that collection methodologies involving time windows of 1 h or longer need to take into account such rapid changes in levels of excreted hormone. We advocate the use of methodological and statistical corrections to decrease the impact of short-term fluctuations in urinary cortisol.
行为内分泌学家意识到许多激素呈现出昼夜节律，并试图通过仅在不同时长的特定时间窗口内收集生理样本，来校正这种模式。在利用尿液测量激素水平的研究中，这个时间窗口通常跨度为2小时或更长。在本研究中，我们比较了在彼此1小时内收集的样本对中的黑猩猩尿液皮质醇水平，以试图验证样本收集时间窗口的使用。黑猩猩饲养于路易斯安那大学新伊比利亚研究中心，并经过训练能按指令尿入纸杯；本分析共纳入41对样本。我们发现，在彼此1小时或更短时间内收集的两组样本中的平均皮质醇水平存在显著差异；第一组样本的平均皮质醇水平显著高于第二组。这种激素的昼夜分泌模式导致了在非常短的时间段内出现这种显著下降。我们得出结论，涉及1小时或更长时间窗口的收集方法需要考虑排泄激素水平的这种快速变化。我们主张采用方法学和统计学校正，以减少尿皮质醇短期波动的影响。
