LIGHT SUPPRESSION OF NOCTURNAL HUMAN MELATONIN SECRETION

光抑制夜间人体褪黑激素的分泌

• 批准号: 4696475
• 负责人: T A WEHR
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF MENTAL HEALTH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/4696475
• 关键词: bioperiodicity; blood chemistry; chronotherapy; circadian rhythms; clinical biomedical equipment; hormone regulation /control mechanism; human subject; light intensity; melatonin; nonvisual photosensitivity; phototherapy; psychophysiology; sleep disorders

Melatonin (MT) is secreted by the pineal gland (PG) almost exclusively at night. Our previous work has shown that MT is present in humans and that its nocturnal secretion can be suppressed with bright artificial light (greater than 2000 lux). This effect of light is presumed to be mediated by neural pathways connecting the retina to the PG via the hypothalamus. At the hypothalamic level the effect of light is thought to be mediated by nicotinic cholinergic receptors. Suppression of MT is presently the only index of hypothalamic sensitivity to light. We have shown that humans have a high threshold for light-MT effects compared with experimental animals. Ordinary artificial light, for example, appears ineffective in humans. Abnormal hypothalamic sensitivity to light may be an important trait and pathogenic mechanism in manic-depressive illness, seasonal affective disorder and delayed sleep phase syndrome. The purpose of this project is (1) to standardize the light-MT suppression test (LMST), (2) to identify sources of variance in the LMST (age, sex, prior sleep or waking, prior exposure to light, etc.), and (3) to investigate hypothalamic sensitivity to light using the LMST in the disorders outlined above. We have standardized the administration of light by using high-intensity tungsten lamps. Spectral qualities are controlled by ultraviolet and infrared filters modifying the light projected into a ganzfeld dome, and intensities of light are varied by using neutral density filters. Blood samples are obtained before, during and after light administration. Using these methods a fluence-response curve for the LMST is being generated with the degree of MT suppression expressed as a function of log light intensity (watts/cm2).

褪黑激素（MT）被松果体（PG）分泌 夜晚。 我们以前的工作表明，MT存在于人类中，并且 它的夜间分泌可以用明亮的人造光抑制 （大于2000 lux）。 假定光的这种效果被介导 通过通过下丘脑将视网膜连接到PG的神经途径。 在下丘脑水平上，光的作用被认为是由 烟碱胆碱能受体。 镇压MT目前是唯一的 下丘脑对光的敏感性的索引。 我们已经证明了人类有 与实验动物相比，轻型MT效应的高阈值。 例如，普通的人造光在人类中似乎无效。 下丘脑对光的敏感性异常可能是一个重要的特征，并且 躁狂抑郁症，季节性情感中的致病机制 障碍和延迟睡眠期综合征。 该项目的目的是（1）标准化轻型MT抑制 测试（LMST），（2）确定LMST中差异来源（年龄，性别， 先前的睡眠或醒来，事先暴露于光等），以及（3） 研究下丘脑对光的敏感性，使用LMST 上面概述的疾病。 我们通过使用高强度标准化了光的给药 钨灯。 光谱质量由紫外线和 红外过滤器修改投影到ganzfeld圆顶的光，并 光的强度通过使用中性密度过滤器而变化。 血 样品是在光线给药之前，之中和之后获得的。 使用 这些方法正在生成LMST的通量响应曲线 MT抑制程度表示为原木光强度的函数 （瓦/CM2）。