Foret J, Daurat A, Touitou Y, Aguirre A, Benoit O
Laboratoire d'Etude du Sommeil Unité 296 INSERM, Hôpital Henri-Mondor, Créteil, France.
Chronobiol Int. 1996 May;13(1):35-45. doi: 10.3109/07420529609040840.
Eight healthy subjects were studied during 39-h spans (from 07:00 on one day until 22:00 the second) in which they remained awake. During one experiment, subjects were exposed to 100 lux of light between 18:00 and 8:00, and during a second experiment, they were exposed to 1000 lux during the same time span. Throughout the daytime period, they were exposed to normal daylight (1500 lux or more). The nighttime 1000-lux light treatment suppressed the melatonin metabolite aMT6s, while the 100 lux treatment did not. On the treatment day, the 1000 lux, in comparison to the 100 lux, light treatment resulted in both an elevated temperature minimum and a delay in its clock-time occurrence overnight. No real circadian phase shift in the temperature, urinary melatonin, or cortisol rhythms was detected after light treatment. This study confirmed that nocturnal exposure to lower light intensities is capable of modifying circadian variables more than previously estimated. The immediate effects of all-night light treatment are essentially not different from those of evening light. This may be important if bright light is used to improve alertness of night workers. Whether subsequent daytime alertness and sleep recovery are affected by the protocol used in our study remains to be determined.
八名健康受试者在39小时（从一天的07:00到第二天的22:00）内保持清醒状态接受研究。在一次实验中，受试者在18:00至8:00期间暴露于100勒克斯的光照下，在另一次实验中，他们在相同时间段内暴露于1000勒克斯的光照下。在整个白天期间，他们暴露于正常日光（1500勒克斯或更高）下。夜间1000勒克斯的光照处理抑制了褪黑素代谢物aMT6s，而100勒克斯的处理则没有。在处理当天，与100勒克斯相比，1000勒克斯的光照处理导致最低体温升高且其出现的时钟时间延迟。光照处理后未检测到体温、尿褪黑素或皮质醇节律有真正的昼夜节律相位变化。这项研究证实，夜间暴露于较低光照强度下比之前估计的更能改变昼夜节律变量。通宵光照处理的即时效果与傍晚光照的效果基本没有差异。如果使用强光来提高夜班工人的警觉性，这可能很重要。我们研究中使用的方案是否会影响随后的白天警觉性和睡眠恢复仍有待确定。
