Circadian Rhythmic Pituitary Adrenocorticotropic Activity, Rectal Temperature and Pinnal Mitosis of Starving, Dehydrated C Mice.

Circadian rhythms in pituitary adrenocorticotropic activity, pinnal mitosis and rectal temperature, as well as in the corticosterone content of serum and adrenal, persist in inbred Bagg albino (C) mice deprived of food and water.

Abstract

Circadian rhythms in pituitary adrenocorticotropic activity, pinnal mitosis and rectal temperature, as well as in the corticosterone content of serum and adrenal, persist in inbred Bagg albino (C) mice deprived of food and water. A lead in phase of the rhythm in pituitary ACTH content over the circadian rhythm in serum corticosterone—an aspect of internal timing in a mammal—is apparent in starved and dehydrated mice as well as in mice with food and water available ad libitum. The rhythms in pinnal mitosis and rectal temperature, compared with each other or with the rhythms in adrenal and serum corticosterone, also show statistically significant differences in phase that characterize circadian systems in the absence, as well as presence, of food and water.