title: Effect of prolonged fasting and subsequent refeeding on free-running rhythms of temperature and locomotor activity in rats.
abstract: This study investigated the possible effect(s) of prolonged fasting and subsequent ad lib refeeding on the circadian organization of rats kept in constant darkness. Free-running rhythms of wheel-running activity and body temperature were studied in rats fasted during a 7-day interval followed with ad lib refeeding started either at subjective midday, i.e., CT6 (circadian time 6) or subjective midnight, i.e., CT18. Phase-shifts of temperature acrophases were similar to those of activity acrophases. During fasting, phase-shifts were phase-advanced (1 circadian h on the average) in most cases. During refeeding, they were mostly phase-delays (2 circadian h on the average) independently of the circadian time of refeeding, i.e., ad lib refeeding did not act as a Zeitgeber. In conclusion, prolonged fasting and subsequent refeeding induce opposite effects on the circadian organization.
authors.affiliation: CNRS-URA 1332, Universite Louis Pasteur, Strasbourg, France. challet@neurochem.u-strasbg.fr
authors.forename: E
authors.initials: E
authors.lastname: Challet
authors.forename: P
authors.initials: P
authors.lastname: Pevet
authors.forename: A
authors.initials: A
authors.lastname: Malan
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000502:physiology*; D001835:Body Weight / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology*; D004435:Eating / Q000502:physiology*; D005215:Fasting / Q000523:psychology*; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012044:Regression Analysis