Increased hypocretin-1 (orexin-a) levels in cerebrospinal fluid of rats after short-term forced activity

Increased hypocretin-1 (orexin-a) levels in cerebrospinal fluid of rats after short-term forced activity

Author Martins, PJF Google Scholar
D'Almeida, V Google Scholar
Pedrazzoli, M. Google Scholar
Lin, L. Google Scholar
Mignot, E. Google Scholar
Tufik, S. Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Stanford Univ
Abstract The hypocretins (orexins) are recently discovered neuropeptides initially associated with feeding behavior and sleep regulation. However, the normal function of these peptides is unclear and a number of studies have reported a role in energy homeostasis and locomotor activity. Exercise (or physical activity) is the most powerful way of challenging the internal homeostatic process. This study examines the circadian differences in response to forced activity and homeostatic challenges on hypocretin-1 (Hcrt-1) levels in the cerebrospinal fluid (CSF) of rats. Hcrt-1 levels were decreased after long-term immobilization at the end of active phase (zeigeber time-0, ZT-0) and increased after short-term forced swimming in the rest phase (ZT-8). Nevertheless, no effects were observed after short-term immobilization, total sleep deprivation or cold exposure. We concluded that despite the relation between hypocretins, stress and sleep regulation reported in the literature, short-term total sleep deprivation, immobilization and cold exposure did not induce increases in CSF Hcrt-1 levels at ZT-0 and ZT-8. On the other hand, the relationship between hypocretinergic system activation and motor activation is reinforced by decrease in Hcr-1 levels after long-term immobilization at ZT-0 and its increased levels after short-term forced swimming at ZT-8 in CSF of rats. (C) 2003 Elsevier B.V. All rights reserved.
Keywords sleep deprivation
Language English
Date 2004-03-15
Published in Regulatory Peptides. Amsterdam: Elsevier B.V., v. 117, n. 3, p. 155-158, 2004.
ISSN 0167-0115 (Sherpa/Romeo, impact factor)
Publisher Elsevier B.V.
Extent 155-158
Access rights Closed access
Type Article
Web of Science ID WOS:000188956500001

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