Abstract | BACKGROUND: OBJECTIVES: METHODS: Changes in cumulative food intake were measured after peripheral administration of ghrelin (1 and 2 nmol/10 g) and the ghrelin-receptor antagonist (D-Lys(3))-GHRP-6 (66.6 and 133.3 nmol/10 g) in obese and lean control mice during the light and dark cycle as well as in a state of food restriction. Hypothalamic ghrelin and ghrelin-receptor expression was measured in ob/ob and lean mice at two different timepoints. RESULTS:
Ghrelin increased food intake in lean and obese mice in the light and dark cycle, whereas the ghrelin-receptor antagonist caused significantly stronger reduction in food intake in obese mice only in the dark cycle. After fasting, ob/ob mice displayed decreased light cycle sensitivity to the anorexigenic effects of the ghrelin-receptor antagonist. Hypothalamic expression levels of ghrelin were unaltered during the light cycle but decreased during the dark cycle in ob/ob mice; whereas, although unchanged in the light cycle, ghrelin-receptor expression was increased in the dark cycle in obese mice. CONCLUSION: The functionality and sensitivity of the ghrelinergic system is dependent on the time of day and the satiety state in leptin-deficient ob/ob mice.
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Authors | Beate C Finger, Harriët Schellekens, Timothy G Dinan, John F Cryan |
Journal | Psychopharmacology
(Psychopharmacology (Berl))
Vol. 216
Issue 3
Pg. 421-9
(Aug 2011)
ISSN: 1432-2072 [Electronic] Germany |
PMID | 21373788
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- GHRP-6, Lys(3)-
- Ghrelin
- Leptin
- Ligands
- Oligopeptides
- Receptors, Ghrelin
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Topics |
- Animals
- Disease Models, Animal
- Eating
(drug effects)
- Ghrelin
(genetics, pharmacology)
- Hypothalamus
(metabolism)
- Leptin
(deficiency)
- Ligands
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Mutant Strains
- Obesity
(metabolism, physiopathology)
- Oligopeptides
(pharmacology)
- Photoperiod
- Real-Time Polymerase Chain Reaction
- Receptors, Ghrelin
(antagonists & inhibitors, genetics)
- Satiation
(drug effects)
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