title: Bright light suppresses melatonin in blind patients with neuronal ceroid-lipofuscinoses.
abstract: We studied whether light information can reach the pineal glands of clinically blind patients with neuronal ceroid-lipofuscinoses. The suppression of melatonin by light was used as an indicator. Seven patients and seven control subjects were exposed to 3,000-lux light for 60 minutes at the rising phase of the melatonin synthesis. Most patients were not cooperative, and their eyelids were opened by a researcher every 2 minutes for 2 seconds. The control subjects opened and closed their eyes similarly by themselves. Light suppressed melatonin in three of seven control subjects and in all patients. The average postlight levels were 80% (control subjects) and 51% (patients) of the corresponding levels during the dim-light session. Despite degenerated retinas of the blind patients, light can penetrate their visual system to the hypothalamic and pineal levels and regulate neuroendocrine function.
authors.affiliation: Institute of Biomedicine, Department of Physiology, Hospital for Children and Adolescents, University of Helsinki, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Hätönen
authors.forename: M L
authors.initials: ML
authors.lastname: Laakso
authors.forename: H
authors.initials: H
authors.lastname: Heiskala
authors.forename: A
authors.initials: A
authors.lastname: Alila-Johansson
authors.forename: K
authors.initials: K
authors.lastname: Sainio
authors.forename: P
authors.initials: P
authors.lastname: Santavuori
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001766:Blindness / Q000150:complications / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008027:Light; D008297:Male; D008550:Melatonin / Q000096:biosynthesis / Q000378:metabolism*; D009472:Neuronal Ceroid-Lipofuscinoses / Q000150:complications / Q000503:physiopathology*; D012636:Secretory Rate / Q000528:radiation effects
chemical_list: D008550:Melatonin