Ekkel E D, Dieleman S J, Schouten W G, Portela A, Cornélissen G, Tielen M J, Halberg F
Department of Herd Health and Reproduction, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
Physiol Behav. 1996 Sep;60(3):985-9. doi: 10.1016/0031-9384(96)00107-2.
Single and population-mean cosinor analyses document a circadian rhythm in salivary cortisol of pigs (p < 0.001). The midline estimated statistic of rhythm, the MESOR (M), is 1.50 +/- 0.07 ng/ml. For the group of 14 pigs studied there was a predictable variation of 64% around this mean in salivary cortisol within a day: the double circadian amplitude, 2A, was 0.96 ng/ml, with a 95% confidence interval ranging from 0.60 to 1.32 ng/ml. A measure of timing, the acrophase, phi, was 10 h 52 min from the phase reference (0030, the middle of the daily dark span of the 24-h light-dark cycle in which the pigs were kept). The 95% confidence interval of phi extended from 9 h 48 min to 12 h 12 min from the reference time. The chronobiologic approach provides indispensable quantitive characteristics as reference standards for future basic or applied work.
单样本和群体均值余弦分析表明，猪唾液皮质醇存在昼夜节律（p < 0.001）。节律的中线估计统计量，即MESOR（M）为1.50±0.07 ng/ml。在研究的14头猪群体中，一天内唾液皮质醇围绕该均值存在64%的可预测变化：双昼夜振幅2A为0.96 ng/ml，95%置信区间为0.60至1.32 ng/ml。作为时间测量指标的峰值时相φ距离相位参考点（0030，即猪所在的24小时明暗循环中每日黑暗时段的中间时间）为10小时52分钟。φ的95%置信区间从参考时间起为9小时48分钟至12小时12分钟。时间生物学方法提供了不可或缺的定量特征，作为未来基础或应用研究的参考标准。
