Functional variability in corticosteroid receptors is a major component of strain differences in fat deposition and metabolic consequences of enriched diets in rat.
Metabolism. 2011-05-01; 60(5): 706-719
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1. Metabolism. 2011 May;60(5):706-19. doi: 10.1016/j.metabol.2010.07.005. Epub 2010
Functional variability in corticosteroid receptors is a major component of strain
differences in fat deposition and metabolic consequences of enriched diets in
Marissal-Arvy N(1), Langlois A, Tridon C, Mormede P.
(1)Université de Bordeaux 2, Laboratoire PsyNuGen, 146 rue Léo-Saignat, INRA
UMR1286, CNRS UMR5226, F-33076 Bordeaux, France.
We aimed to distinguish mineralocorticoid (MR) from glucocorticoid receptor (GR)
actions in the nutritional differences between the Fischer 344 (F344) and LOU/C
(LOU) rat strains. The decrease of urinary Na+/K+ ratio induced via MR activation
by aldosterone and decrease of circulating lymphocyte counts exerted via GR
activation by dexamethasone revealed a higher efficiency of corticosteroid
receptor in LOU than in F344 rats. Afterward, we submitted F344 and LOU male rats
to adrenalectomy and to substitution treatments with agonists of MR or GR under 3
successive diets–standard, free choice between chow and pork lard, and an
imposed high-fat/high-sugar diet–to explore the involvement of the interactions
between activation of corticosteroid receptors and diet on food intake, body
composition, and metabolic blood parameters in these rats. Lastly, we measured
energy expenditure and substrate oxidization in various experimental conditions
in LOU and F344 rats by indirect calorimetry. In LOU rats, we showed greater
basal and MR-induced energy expenditure, diet-induced thermogenesis, and lipid
oxidization. We showed that the F344 rat strain constitutes a relevant model of
the unfavorable effects exerted by glucocorticoids via GR on food preference for
high-calorie diets, abdominal fat deposition, diabetes, and other deleterious
consequences of visceral obesity. Contrary to F344 rats, the LOU rats did not
exhibit the expected visceral fat deposition linked to GR activation. This strain
is therefore a relevant model of resistance to diet-induced obesity and to the
deleterious effects exerted by glucocorticoids on metabolism.
Copyright © 2011 Elsevier Inc. All rights reserved.
PMID: 20723946 [Indexed for MEDLINE]