Thermoregulatory effects of melatonin in relation to sleepiness
| Autor: | Kurt Kräuchi, Christian Cajochen, Anna Wirz-Justice, Josef Flammer, Mona Pache |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Adult
Male medicine.medical_specialty Sympathetic nervous system Hot Temperature Time Factors Physiology Sleep induction Biology Models Biological Arousal Melatonin Orthostatic vital signs Physiology (medical) Internal medicine medicine Humans Circadian rhythm Sleep Stages Temperature Thermoregulation Circadian Rhythm medicine.anatomical_structure Endocrinology Skin Temperature Sleep hormones hormone substitutes and hormone antagonists Body Temperature Regulation medicine.drug |
| Zdroj: | Chronobiology International. 23:475-484 |
| ISSN: | 1525-6073 0742-0528 |
| DOI: | 10.1080/07420520500545854 |
| Popis: | Thermoregulatory processes have long been implicated in the initiation of human sleep. In this paper, we review our own studies conducted over the last decade showing a crucial role for melatonin as a mediator between the thermoregulatory and arousal system in humans. Distal heat loss, via increased skin temperature, seems to be intimately coupled with increased sleepiness and sleep induction. Exogenous melatonin administration during the day when melatonin is essentially absent mimics the endogenous thermophysiological processes occurring in the evening and induces sleepiness. Using a cold thermic challenge test, it was shown that melatonin-induced sleepiness occurs in parallel with reduction in the thermoregulatory set-point (threshold); thus, melatonin may act as a circadian modulator of the thermoregulatory set-point. In addition, an orthostatic challenge can partially block the melatonin-induced effects, suggesting an important role of the sympathetic nervous system as a link between the thermoregulatory and arousal systems. A topographical analysis of finger skin temperature with infrared thermometry revealed that the most distal parts of the fingers, i.e., fingertips, represent the important skin regions for heat loss regulation, most probably via opening the arteriovenous anastomoses, and this is clearly potentiated by melatonin. Taken together, melatonin is involved in the fine-tuning of vascular tone in selective vascular beds, as circulating melatonin levels rise and fall throughout the night. Besides the role of melatonin as "nature's soporific", it can also serve as nature's nocturnal vascular modulator. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|