AJP - Regu Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Regul Integr Comp Physiol 277: R1376-R1384, 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 Davidson, A. J.
Right arrow Articles by Stephan, F. K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Davidson, A. J.
Right arrow Articles by Stephan, F. K.
Vol. 277, Issue 5, R1376-R1384, November 1999

Feeding-entrained circadian rhythms in hypophysectomized rats with suprachiasmatic nucleus lesions

Alec J. Davidson and Friedrich K. Stephan

Neuroscience Program, Department of Psychology, Florida State University, Tallahassee, Florida 32303-1270

Several pituitary hormones are important in the regulation of metabolism, and their release appears to be controlled by a circadian clock. Consequently, they may be involved in feeding-entrained circadian rhythms. Hypophysectomized (Hypox) and sham-operated male Sprague-Dawley rats had access to food for 4 h each day. Food-anticipatory activity (FAA) and core body temperature (Tb) were monitored. Both groups entrained to the daily meal with an increase in activity in the 4 h preceding meal access and quickly reentrained after an 8-h phase advance of food access. FAA was not disrupted in either group after suprachiasmatic lesions were added. Core Tb increased in the sham-operated subjects before mealtime, but Hypox rats failed to show this effect. Rather, Tb declined during anticipation and throughout the food access period. Respiratory quotient (RQ), an indirect measure of metabolic rate, was measured for 24 h in some subjects. Sham-operated rats showed a dramatic downturn in RQ 1 h before mealtime, whereas Hypox rats showed a steadily decreasing RQ throughout the day. The results show that the pituitary hormones are not necessary for FAA and that in Hypox rats the anticipatory rise in Tb and changes in RQ become dissociated from anticipatory behavior, indicating that these functions are separate outputs of the food-entrainable circadian oscillator.

body temperature; metabolism; pituitary; respiratory quotient


This article has been cited by other articles:


Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
G. J. Landry, M. M. Simon, I. C. Webb, and R. E. Mistlberger
Persistence of a behavioral food-anticipatory circadian rhythm following dorsomedial hypothalamic ablation in rats
Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2006; 290(6): R1527 - R1534.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
Y. Satoh, H. Kawai, N. Kudo, Y. Kawashima, and A. Mitsumoto
Time-restricted feeding entrains daily rhythms of energy metabolism in mice
Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2006; 290(5): R1276 - R1283.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
S. Pitts, E. Perone, and R. Silver
Food-entrained circadian rhythms are sustained in arrhythmic Clk/Clk mutant mice
Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2003; 285(1): R57 - R67.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
A. J. Davidson, S. L. T. Cappendijk, and F. K. Stephan
Feeding-entrained circadian rhythms are attenuated by lesions of the parabrachial region in rats
Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2000; 278(5): R1296 - R1304.
[Abstract] [Full Text] [PDF]


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