Endocrinology, Vol 123, 1934-1941, Copyright © 1988 by Endocrine Society

ARTICLES

The effects of acute and life-long food restriction on basal and stress- induced serum corticosterone levels in young and aged rats

J Stewart, MJ Meaney, D Aitken, L Jensen and N Kalant
Department of Psychology, Concordia University, Montreal, Canada.

The effects of short term (1-month) and life-long 60% ad libitum food restriction on the adrenocortical response to restraint stress were compared in young and aged Fischer 344 rats. In rats restricted for 1 month (study 1), the adrenocortical response differed as a function of age. In 8-month-old animals, the initial steep rise in corticosterone in response to stress was of similar magnitude in ad libitum and restricted animals. In 23-month-old animals the corticosterone response was severely blunted in restricted animals. In life-long restricted animals (study 2), the corticosterone response to restraint stress was tested at 8, 16, and 24 months of age. The general pattern of response to stress in these animals was similar to that in study 1. The 16- and 24-month-old animals showed the same blunted response to stress found in the 23-month-old animals restricted for only 1 month, suggesting that the severe restriction per se and not life-long food restriction blunted the response to stress in aged animals. The similarity between the response to stress in study 1 and study 2 was evident even though animals were tested in one case before feeding when corticosterone levels were high, and in the other 4-5 h after feeding when corticosterone levels were lower. In study 3 it was found that in food- restricted young rats, the mean corticosterone level over a 24-h period was significantly elevated above that in ad libitum fed young rats. In aged rats, however, except before daily feeding, corticosterone levels of food-restricted rats remained significantly below those of ad libitum fed animals, whose levels were, in turn, significantly elevated compared to those of ad libitum fed young rats. These findings suggest that in aged animals severe food restriction reduces basal corticosterone levels, adrenal responsiveness to stress, and adrenal size and has the potential to protect against the consequences of high corticosterone levels in aging.

This article has been cited by other articles:

				A. L. Jaquiery, M. H. Oliver, F. H. Bloomfield, K. L. Connor, J. R. G. Challis, and J. E. Harding Fetal exposure to excess glucocorticoid is unlikely to explain the effects of periconceptional undernutrition in sheep J. Physiol., April 1, 2006; 572(1): 109 - 118. [Abstract] [Full Text] [PDF]

				C. D. Conrad What Is the Functional Significance of Chronic Stress-Induced CA3 Dendritic Retraction Within the Hippocampus? Behav Cogn Neurosci Rev, March 1, 2006; 5(1): 41 - 60. [Abstract] [PDF]

				E.-S. Han, T. R. Evans, J. H. Shu, S. Lee, and J. F. Nelson Food Restriction Enhances Endogenous and Corticotropin-Induced Plasma Elevations of Free but Not Total Corticosterone Throughout Life in Rats J. Gerontol. A Biol. Sci. Med. Sci., September 1, 2001; 56(9): B391 - 397. [Abstract] [Full Text] [PDF]

				J. Lesage, B. Blondeau, M. Grino, B. Bréant, and J. P. Dupouy Maternal Undernutrition during Late Gestation Induces Fetal Overexposure to Glucocorticoids and Intrauterine Growth Retardation, and Disturbs the Hypothalamo-Pituitary Adrenal Axis in the Newborn Rat Endocrinology, May 1, 2001; 142(5): 1692 - 1702. [Abstract] [Full Text]

				E.-S. Han, T. R. Evans, and J. F. Nelson Adrenocortical Responsiveness to Adrenocorticotropic Hormone Is Enhanced in Chronically Food-Restricted Rats J. Nutr., September 1, 1998; 128(9): 1415 - 1420. [Abstract] [Full Text]