title: Fentanyl, a upsilon-opioid receptor agonist, phase shifts the hamster circadian pacemaker.
abstract: The phase-shifting effects of the mu-opioid receptor agonist fentanyl on the circadian timing system were investigated in the hamster. Fentanyl injections during the mid-subjective day induced phase advances of the hamsters' wheel-running activity rhythm. The shifts were not accompanied by an increase in locomotor activity but instead a decrease of activity was often observed. A dose-response curve indicated that with increasing dosage, the response probability increased, while the magnitude of the induced shift remained stable. The present data suggest that there is some role for opioid regulation of the circadian system.
authors.affiliation: Department of Physiology, Leiden University Medical Center, Leiden, The Netherlands. j.h.meijer@physiology.medfac.leidenuniv.nl
authors.forename: J H
authors.initials: JH
authors.lastname: Meijer
authors.forename: A C
authors.initials: AC
authors.lastname: Ruijs
authors.forename: H
authors.initials: H
authors.lastname: Albus
authors.forename: B
authors.initials: B
authors.lastname: van de Geest
authors.forename: H
authors.initials: H
authors.lastname: Duindam
authors.forename: A H
authors.initials: AH
authors.lastname: Zwinderman
authors.forename: A
authors.initials: A
authors.lastname: Dahan
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects*; D006224:Cricetinae; D005283:Fentanyl / Q000494:pharmacology*; D008297:Male; D008647:Mesocricetus; D017450:Receptors, Opioid, mu / Q000819:agonists / Q000502:physiology*; D013477:Superior Colliculi / Q000502:physiology
chemical_list: D000701:Analgesics, Opioid; D017450:Receptors, Opioid, mu; D005283:Fentanyl