| Hypothalamic paraventricular 5-hydroxytryptamine inhibits the effects of ghrelin on eating and energy substrate utilization. | |
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MedLine Citation:
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PMID: 20573591 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Ghrelin microinjections into discrete regions of the hypothalamus, including the paraventricular nucleus (PVN), stimulate eating and promote carbohydrate oxidation, effects similar to PVN microinjection of neuropeptide Y (NPY). We have also reported that NPY's orexigenic and metabolic effects are antagonized by pretreatment with 5-hydroxytryptamine (5-HT) or 5-HT receptor agonists. In order to determine whether 5-HT also inhibits ghrelin's orexigenic and metabolic actions, the present study examined the effects of 5-HT pretreatment on ghrelin-induced alterations in eating and energy substrate utilization following direct injections into the hypothalamic PVN. Both 5-HT (5-20 nmol) and ghrelin (100 pmol) were administered at the onset of the dark cycle. Food intake was measured 2h postinjection. A separate group of rats (n=8) was injected with 5-HT paired with ghrelin and respiratory quotient (RQ; VCO(2)/VO(2)) was measured over 2h using an open circuit calorimeter. PVN injections of ghrelin increased food intake and increased RQ, reflecting a shift in energy substrate utilization in favor of carbohydrate oxidation. 5-HT effectively blocked the effects of ghrelin on both food intake and RQ. We then administered the 5-HT(2A/2C), receptor agonist, DOI, immediately prior to ghrelin. Similar to 5-HT, PVN DOI blocked ghrelin-induced eating and inhibited the peptide's effect on substrate utilization. These data are in agreement with other evidence suggesting that ghrelin functions as a gut-brain peptide in the control of food intake and energy metabolism, and indicate that 5-HT acts within the PVN to modulate ghrelin's orexigenic and metabolic signaling. |
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Authors:
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Paul J Currie; Catherine S John; Marjorie L Nicholson; Colin D Chapman; Katherine E Loera |
Publication Detail:
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Type: Comparative Study; Journal Article; Research Support, N.I.H., Extramural Date: 2010-06-02 |
Journal Detail:
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Title: Pharmacology, biochemistry, and behavior Volume: 97 ISSN: 1873-5177 ISO Abbreviation: Pharmacol. Biochem. Behav. Publication Date: 2010 Nov |
Date Detail:
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Created Date: 2010-10-11 Completed Date: 2011-09-15 Revised Date: 2013-05-29 |
Medline Journal Info:
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Nlm Unique ID: 0367050 Medline TA: Pharmacol Biochem Behav Country: United States |
Other Details:
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Languages: eng Pagination: 152-5 Citation Subset: IM |
Copyright Information:
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Copyright © 2010 Elsevier Inc. All rights reserved. |
Affiliation:
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Department of Psychology, Reed College, Portland, OR 97202, USA. pcurrie@reed.edu |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Eating / drug effects*, physiology Energy Metabolism / drug effects*, physiology Ghrelin / administration & dosage*, antagonists & inhibitors*, physiology Male Microinjections Paraventricular Hypothalamic Nucleus / drug effects*, physiology Rats Rats, Sprague-Dawley Serotonin / administration & dosage* Substrate Specificity / drug effects, physiology |
| Grant Support | |
ID/Acronym/Agency:
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070496-01A1//PHS HHS |
| Chemical | |
Reg. No./Substance:
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0/Ghrelin; 50-67-9/Serotonin |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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