Adrenocortical responsiveness to adrenocorticotropic hormone is enhanced in chronically food-restricted rats

Eun Soo Han, Ted R. Evans, James F Nelson

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Chronic food restriction (FR) of rats and mice results in moderate hyperadrenocorticism, which may play a role in activating cellular mechanisms that retard aging. Previously, we reported that the FR-induced hyperadrenocorticism is not due to an activated hypothalamo-pituitary unit. Therefore, we investigated in a series of experiments whether adrenal responsiveness to adrenocorticotropic hormone (ACTH), in vitro and in vivo, is enhanced by FR. Three mo-old male Fischer 344 rats were either given free access to food (AL rats) or restricted to 60% of food consumed by AL rats (FR rats) from 6 wk of age. They were killed by decapitation in the morning (AM) and afternoon (PM) when endogenously circulating corticosterone levels are at their nadir and peak, respectively. In vitro, adrenal glands from FR rats (1.5 mo FR) produced more corticosterone per mg at all doses of ACTH than those from AL rats in both the AM and PM (diet main effect, P < 0.001). FR (1.5 to 2.5 mo) also enhanced adrenal responsiveness to physiologic (diet main effect, P < 0.05) and superphysiologic (diet main effect, P < 0.001) levels of ACTH administered in vivo to dexamethasone-treated rats. ACTH- receptor (ACTH-R) mRNA, normalized to adrenal mass or to total RNA, was not influenced by FR (1.5 mo). However, adrenal ACTHR mRNA, as well as adrenal mass, per unit body weight was greater in FR than in AL rats (diet main effect, P 0.001). These results indicate that enhanced adrenocortical responsiveness to ACTH plays a major role in the hyperadrenocortical state of chronically FR rats.

Original languageEnglish (US)
Pages (from-to)1415-1420
Number of pages6
JournalJournal of Nutrition
Volume128
Issue number9
StatePublished - Sep 1998

Fingerprint

corticotropin
Adrenocorticotropic Hormone
Food
rats
hyperadrenocorticism
Adrenocortical Hyperfunction
Diet
corticosterone
diet
Corticosterone
Corticotropin Receptors
decapitation
adrenal glands
Decapitation
hormone receptors
dexamethasone
Messenger RNA
Inbred F344 Rats
Adrenal Glands
Dexamethasone

Keywords

  • Adrenal sensitivity
  • Corticosterone
  • Male Fischer 344 rats food restriction

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Food Science

Cite this

Adrenocortical responsiveness to adrenocorticotropic hormone is enhanced in chronically food-restricted rats. / Han, Eun Soo; Evans, Ted R.; Nelson, James F.

In: Journal of Nutrition, Vol. 128, No. 9, 09.1998, p. 1415-1420.

Research output: Contribution to journalArticle

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