AJP - Regu Ad Instruments
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Regul Integr Comp Physiol 277: R812-R828, 1999;
0363-6119/99 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Pitrosky, B.
Right arrow Articles by Pevet, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Pitrosky, B.
Right arrow Articles by Pevet, P.
Vol. 277, Issue 3, R812-R828, September 1999

Organization of rat circadian rhythms during daily infusion of melatonin or S20098, a melatonin agonist

B. Pitrosky1, R. Kirsch1, A. Malan1, E. Mocaer2, and P. Pevet1

1 Neurobiologie des Fonctions Rythmiques et Saisonnières, UMR-CNRS 7518, Université Louis Pasteur, 67000 Strasbourg; and 2 Institut de Recherches Internationales Servier, Place des Pléïades, 92415 Courbevoie, France

Daily administration of melatonin or S20098, a melatonin agonist, is known to entrain the free-running circadian rhythms of rats. The effects of the duration of administration on entrainment were studied. The animals demonstrated free-running circadian rhythms (running-wheel activity, body temperature, general activity) in constant darkness. Daily infusions of melatonin or S20098 for 1, 8, or 16 h entrained the circadian rhythms to 24 h. Two daily infusions of 1 h (separated by 8 h) entrained the activity peak within the shorter time interval. The entraining properties of melatonin and S20098 were similar and were affected neither by pinealectomy nor by infusion of 1- or 8-h duration. However, with 16-h infusion, less than half of the animals became entrained. Once entrained, the phase angle between the onset of infusion and the rhythms (onset of activity or acrophase of body temperature) increased with the duration of infusion. Before entrainment, the free-running period increased with the duration of infusion, an effect that was not predictable from the phase response curve.

entrainment


This article has been cited by other articles:


Home page
 Pharmacol. Rev.Home page
V. Simonneaux and C. Ribelayga
Generation of the Melatonin Endocrine Message in Mammals: A Review of the Complex Regulation of Melatonin Synthesis by Norepinephrine, Peptides, and Other Pineal Transmitters
Pharmacol. Rev., June 1, 2003; 55(2): 325 - 395.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
O. Van Reeth, L. Weibel, E. Olivares, S. Maccari, E. Mocaer, and F. W. Turek
Melatonin or a melatonin agonist corrects age-related changes in circadian response to environmental stimulus
Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2001; 280(5): R1582 - R1591.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online