Ghrelin-induced adiposity is independent of orexigenic effects.

Abstract

Ghrelin is a hormone produced predominantly by the stomach that targets a number of specific areas in the central nervous system to promote a positive energy balance by increasing food intake and energy storage. In that respect, similarities exist with the effects of consuming a high-fat diet (HFD), which also increases caloric intake and the amount of stored calories. We determined whether the effects of ghrelin on feeding and adiposity are influenced by the exposure to an HFD. Chronic intracerebroventricular ghrelin (2.5 nmol/d) increased feeding in lean rats fed a low-fat control diet (CD) [192 ± 5 g (ghrelin+CD) vs. 152 ± 5 g (control i.c.v. saline+CD), P<0.001], but the combination of ghrelin plus HFD did not result in significantly greater hyperphagia [150 ± 7 g (ghrelin+HFD) vs. 136 ± 4 g (saline+HFD)]. Despite failing to increase food intake in rats fed the HFD, ghrelin nonetheless increased adiposity [fat mass increase of 14 ± 2 g (ghrelin+HFD) vs. 1 ± 1 g (saline+HFD), P<0.001] up-regulating the gene expression of lipogenic enzymes in white adipose tissue. Our findings demonstrate that factors associated with high-fat feeding functionally interact with pathways regulating the effect of ghrelin on food intake. We conclude that ghrelin's central effects on nutrient intake and nutrient partitioning can be separated and suggest an opportunity to identify respective independent neuronal pathways.

• Authors: Diego Perez-Tilve, Kristy Heppner, Henriette Kirchner, Sarah H Lockie, Stephen C Woods, David L Smiley, Matthias Tschöp, Paul Pfluger
• Journal: FASEB journal : official publication of the Federation of American Societies for Experimental Biology (FASEB J) Vol. 25 Issue 8 Pg. 2814-22 (Aug 2011) ISSN: 1530-6860 [Electronic] United States
• PMID: 21543764 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Dietary Fats
• Ghrelin
• Melanocortins
• Neuropeptides
• Receptors, Neuropeptide

Topics

• Adipose Tissue, White (drug effects, physiology)
• Adiposity (drug effects, physiology)
• Animals
• Dietary Fats (administration & dosage)
• Eating (drug effects, physiology)
• Ghrelin (administration & dosage, pharmacology, physiology)
• Hyperphagia (etiology, physiopathology)
• Hypothalamus, Middle (drug effects, physiology)
• Infusions, Intraventricular
• Lipogenesis (drug effects, genetics, physiology)
• Male
• Melanocortins (antagonists & inhibitors, physiology)
• Neuropeptides (physiology)
• Rats
• Rats, Long-Evans
• Rats, Wistar
• Receptors, Neuropeptide (physiology)
• Signal Transduction (drug effects, physiology)
• Up-Regulation