SUPPRESSION OF MELATONIN SECRETION IN SOME BLIND PATIENTS BY EXPOSURE TO BRIGHT LIGHT
SUPPRESSION OF MELATONIN SECRETION IN SOME BLIND PATIENTS BY EXPOSURE TO BRIGHT LIGHT
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DOI：
10.1056/nejm199501053320102
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发表时间：
1995-01-05
影响因子：
158.5
通讯作者：
RIZZO, JF
中科院分区：
文献类型：
--
作者：
CZEISLER, CA;SHANAHAN, TL;RIZZO, JF
背景完全失明通常会导致昼夜节律与24小时节律不同步，并导致复发性失眠。然而，一些盲人患者保持昼夜节律夹带。我们进行了这项研究，以确定是否一些盲人的眼睛传达足够的光信息，夹带下丘脑昼夜节律起搏器酸抑制褪黑激素的分泌，尽管明显完全丧失视觉功能。我们评估了输入的光的昼夜节律起搏器测试的能力，明亮的光，以减少血浆褪黑激素浓度在11个盲人患者没有意识的光的感知和6个正常人。我们还评估了盲人患者随时间的昼夜节律夹带。在暴露于强光下的过程中，三名失明患者的血浆褪黑激素浓度平均（+/-SD）下降了69+/-21%，而正常受试者平均下降了66+/-15%。当其中两名盲人在暴露于光下的情况下进行测试时，血浆褪黑激素并没有减少。三名盲人患者报告没有睡眠困难，并保持明显的昼夜节律夹带到24小时。血浆褪黑激素浓度并没有减少暴露在明亮的光在7个其余的盲人患者，在第八，血浆褪黑激素是检测不到的。这8名患者报告了失眠史，4名患者的昼夜温度节律未被带入24小时。视觉子系统介导的光诱导的褪黑激素分泌的抑制仍然在一些失明患者的功能完整。因此，缺乏对昼夜节律系统的光输入构成了一种独特的失明形式，与周期性失眠有关，这折磨着大多数但不是所有没有有意识感知光的患者。
Background. Complete blindness generally results in the loss of synchronization of circadian rhythms to the 24-hour day and in recurrent insomnia. However, some blind patients maintain circadian entrainment. We undertook this study to determine whether some blind patients' eyes convey sufficient photic information to entrain the hypothalamic circadian pacemaker acid suppress melatonin secretion, despite an apparently complete loss of visual function.Methods. We evaluated the input of light to the circadian pacemaker by testing the ability of bright light to decrease plasma melatonin concentrations in 11 blind patients with no conscious perception of light and in 6 normal subjects. We also evaluated circadian entrainment over time in the blind patients.Results. Plasma melatonin concentrations decreased during exposure to bright light in three sightless patients by an average (+/-SD) of 69+/-21 percent and in the normal subjects by an average of 66+/-15 percent. When two of these blind patients were tested with their eyes covered during exposure to light, plasma melatonin did not decrease. The three blind patients reported no difficulty sleeping and maintained apparent circadian entrainment to the 24-hour day. Plasma melatonin concentrations did not decrease during exposure to bright light in seven of the remaining blind patients; in the eighth, plasma melatonin was undetectable. These eight patients reported a history of insomnia, and in four the circadian temperature rhythm was not entrained to the 24-hour day.Conclusions. The visual subsystem that mediates the light-induced suppression of melatonin secretion remains functionally intact in some sightless patients. The absence of photic input to the circadian system thus constitutes a distinct form of blindness, associated with periodic insomnia, that afflicts most but not ail patients with no conscious perception of light.