Faculty Collaboration Database

Plasma leptin and ghrelin in the neonatal rat: interaction of dexamethasone and hypoxia. J Endocrinol 2005 Jun;185(3):477-84

Date

06/03/2005

Pubmed ID

15930174

Pubmed Central ID

PMC1249478

DOI

10.1677/joe.1.06159

Scopus ID

2-s2.0-21244504248 (requires institutional sign-in at Scopus site)   29 Citations

Abstract

Ghrelin, leptin, and endogenous glucocorticoids play a role in appetite regulation, energy balance, and growth. The present study assessed the effects of dexamethasone (DEX) on these hormones, and on ACTH and pituitary proopiomelanocortin (POMC) and corticotropin-releasing hormone receptor-1 (CRHR1) mRNA expression, during a common metabolic stress - neonatal hypoxia. Newborn rats were raised in room air (21% O2) or under normobaric hypoxia (12% O2) from birth to postnatal day (PD) 7. DEX was administered on PD3 (0.5 mg/kg), PD4 (0.25 mg/kg), PD5 (0.125 mg/kg), and PD6 (0.05 mg/kg). Pups were studied on PD7 (24 h after the last dose of DEX). DEX significantly increased plasma leptin and ghrelin in normoxic pups, but only increased ghrelin in hypoxic pups. Hypoxia alone resulted in a small increase in plasma leptin. Plasma corticosterone and pituitary POMC mRNA expression were decreased 24 h following the last dose of DEX, whereas plasma ACTH and pituitary CRHR1 mRNA expression had already increased (normoxia and hypoxia). Hypoxia alone increased corticosterone, but had no effect on ACTH or pituitary POMC and CRHR1 mRNA expression. Neonatal DEX treatment, hypoxia, and the combination of both affect hormones involved in energy homeostasis. Pituitary function in the neonate was quickly restored following DEX-induced suppression of the hypothalamic-pituitary-adrenal axis. The changes in ghrelin, leptin, and corticosterone may be beneficial to the hypoxic neonate through the maintenance of appetite and shifts in intermediary metabolism.

Author List

Bruder ED, Jacobson L, Raff H

Author

Hershel Raff PhD Professor in the Academic Affairs department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adrenocorticotropic Hormone
Animals
Animals, Newborn
Blotting, Northern
Corticosterone
Dexamethasone
Enzyme-Linked Immunosorbent Assay
Female
Ghrelin
Glucocorticoids
Hypoxia
Leptin
Male
Peptide Hormones
Pituitary Gland
Pro-Opiomelanocortin
RNA, Messenger
Rats
Rats, Sprague-Dawley
Receptors, Corticotropin-Releasing Hormone