Nakamura K, Hashimoto S, Honma S, Honma K
Department of Physiology, Hokkaido University School of Medicine, Sapporo, Japan.
Psychiatry Clin Neurosci. 1997 Jun;51(3):121-7. doi: 10.1111/j.1440-1819.1997.tb02373.x.
Effects of daily melatonin intake on the circadian rhythms of sleep and wakefulness, rectal temperature and plasma cortisol were examined in a sighted man who had suffered from the non-24-hour sleep-wake syndrome. The subject lacked the nocturnal melatonin rise in plasma, but showed robust circadian rhythms in rectal temperature and plasma cortisol. The sleep-wake rhythm free-ran with a period longer than 24 hours. Daily melatonin intake at 21:00 h concentrated sleep episodes in the nocturnal period (24:00-8:00 h), and increased the length of the episodes. A single oral dose (3 mg) of melatonin increased plasma melatonin levels to about 1300 pg/mL within one hour and remained at pharmacological levels for approximately 6 hours. The trough of rectal temperature and the circadian rise of plasma cortisol were fixed to the early morning. A higher dose of melatonin (6 mg) did not improve the general feature. After the cessation of melatonin intake, the sleep-wake rhythm began to free-run together with the circadian rhythms in rectal temperature and plasma cortisol. It is concluded that daily intake of melatonin at early night time resets the circadian rhythms in a sighted man who lacked the nocturnal melatonin rise and showed free-running circadian rhythms in routine life.
在一名患有非24小时睡眠-清醒综合征的视力正常男性中，研究了每日服用褪黑素对睡眠和清醒的昼夜节律、直肠温度及血浆皮质醇的影响。该受试者血浆中缺乏夜间褪黑素升高的情况，但直肠温度和血浆皮质醇呈现出明显的昼夜节律。睡眠-清醒节律以超过24小时的周期自由运转。在21:00服用每日剂量的褪黑素可使睡眠时段集中在夜间（24:00 - 8:00），并增加了这些时段的时长。单次口服剂量（3毫克）的褪黑素在一小时内可使血浆褪黑素水平升高至约1300皮克/毫升，并在药理学水平维持约6小时。直肠温度的低谷和血浆皮质醇的昼夜升高固定在清晨。更高剂量（6毫克）的褪黑素并未改善总体情况。停止服用褪黑素后，睡眠-清醒节律开始与直肠温度和血浆皮质醇的昼夜节律一起自由运转。得出的结论是，在夜间早期每日服用褪黑素可使一名缺乏夜间褪黑素升高且在日常生活中呈现自由运转昼夜节律的视力正常男性的昼夜节律重新设定。
