Monteleone P, Fuschino A, Nolfe G, Maj M
Institute of Psychiatry, 1st Medical School, University of Naples, Italy.
Psychoneuroendocrinology. 1992;17(1):81-6. doi: 10.1016/0306-4530(92)90078-l.
It has been shown that, in the rat, physical stress decreases pineal melatonin levels at night, whereas it increases melatonin production during the day. We have demonstrated that nighttime physical exercise is able to blunt the nocturnal surge of plasma melatonin in healthy subjects. Since this effect might be mediated by exercise-induced cortisol secretion from the adrenal gland, in the present investigation we studied the relationship between cortisol and melatonin responses to nighttime physical stress in six healthy men, aged 28-33 yr. The physical stress consisted of bicycling on a bicycle ergometer at 50% of personal maximum work capacity (MWC), followed by another 10 min of bicycling at 80% of MWC. According to our previous data, physical exercise performed between 2240 h and 2300 h significantly reduced the nocturnal surge of plasma melatonin and increased the levels of cortisol. The surge in plasma cortisol preceded the decrease in plasma melatonin concentration. These findings suggest a temporal relationship between plasma cortisol and melatonin responses to physical stress; the causal nature of this relationship remains to be elucidated.
研究表明，在大鼠中，身体应激会降低夜间松果体褪黑素水平，而在白天则会增加褪黑素的分泌。我们已经证明，夜间体育锻炼能够抑制健康受试者血浆褪黑素的夜间激增。由于这种效应可能是由运动诱导的肾上腺皮质醇分泌介导的，在本研究中，我们研究了6名年龄在28 - 33岁的健康男性中皮质醇与褪黑素对夜间身体应激反应之间的关系。身体应激包括在自行车测力计上以个人最大工作能力（MWC）的50%骑自行车，随后再以MWC的80%骑自行车10分钟。根据我们之前的数据，在2240 h至2300 h之间进行体育锻炼可显著降低血浆褪黑素的夜间激增，并增加皮质醇水平。血浆皮质醇的激增先于血浆褪黑素浓度的下降。这些发现表明血浆皮质醇与褪黑素对身体应激反应之间存在时间关系；这种关系的因果性质仍有待阐明。
