Effects of food restriction on circadian adrenocortical rhythm in rats under constant lighting conditions.
Influences of food restriction on the circadian adrenocortical rhythm were studied in blinded and unblinded rats under constant light (LL). Blinded rats, which were allowed to access to food ad libitum, manifested a phase shift of the circadian adrenocortical rhythm. However, restricted feeding between 19.00 and 21.00 h for 4 weeks prevented the phase shift and the peak levels of plasma corticosterone (B) still appeared at 19.00. On the other hand, unblinded rats, allowed to feed ad libitum, showed an abolition of the circadian periodicity of adrenocortical activity 5 weeks after exposing the rats to LL. However, the rhythm, synchronizing with the feeding periods, was promptly recovered under food restriction. These results suggest a synchronizing and generating action of feeding for the circadian adrenocortical rhythm.
D000818:Animals; D001766:Blindness / Q000378:metabolism; D002940:Circadian Rhythm; D003345:Corticosterone / Q000097:blood*; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D008027:Light; D051381:Rats
D003345:Corticosterone