Hypothalamic npy and prepronpy mrna in jungarian hamsters:
sensitivity to food deprivation but not photoperiod.
Mercer, Julian G., C. Bruce Lawrence, Bernard Beck, Arlette Burlet,
Terry Atkinson, and Perry Barrett.
Molecular Neuroendocrinology Group, Rowett Research Institute,
Greenburn Road, Bucksburn, Aberdeen AB2 9SB, Scotland.; and INSERM
U.308 MRCA, 38, rue Lionnois, 54000 Nancy, France
APStracts 2:0179R, 1995.
Two catabolic states leading to loss of body weight were compared in
the Djungarian hamster (Phodopus sungorus campbelli). Hypothalamic
Neuropeptide Y (NPY), and gene expression for NPY and CRF were
examined after either withdrawal of food for 48 h or exposure to
short photoperiod for 10 or 20 weeks. Food deprivation was
accompanied by increases in both NPY peptide and preproNPY mRNA in
the hypothalamic arcuate nucleus (ARC). Increases in gene expression
were limited in comparison with published data from the rat, and were
inversely related to pre deprivation body weight. Exposure to short
photoperiod for 20 weeks reduced body weight by 39% but the activity
of the NPYergic system was not affected; peptide concentration and
gene expression were similar in short photoperiod hamsters and long
photoperiod controls. The hypothalamic NPYergic system of the
Djungarian hamster is sensitive to weight loss due to imposed
manipulations of energy balance, but the catabolism observed in short
photoperiod gives rise to a body weight that is appropriate to the
season encoded by the photoperiod. CRF gene expression was not
affected by food deprivation or short photoperiod.
Received 15 March 1995; accepted in final form 6 June 1995.
APS Manuscript Number R170-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 11 July 1995.