title: Chronic sugar intake dampens feeding-related activity of neurons synthesizing a satiety mediator, oxytocin.
abstract: Increased tone of orexigens mediating reward occurs upon repeated consumption of sweet foods. Interestingly, some of these reward orexigens, such as opioids, diminish activity of neurons synthesizing oxytocin, a nonapeptide that promotes satiety and feeding termination. It is not known, however, whether consumption-related activity of the central oxytocin system is modified under chronic sugar feeding reward itself. Therefore, we examined how chronic consumption of a rewarding high-sucrose (HS) vs. bland cornstarch (CS) diet affected the activity of oxytocin cells in the hypothalamus at the time of meal termination. Schedule-fed (2h/day) rats received either a HS or CS powdered diet for 20 days. On the 21st day, they were given the same or the opposite diet, and food was removed after the main consummatory activity was completed. Animals were perfused 60 min after feeding termination and brains were immunostained for oxytocin and the marker of neuronal activity, c-Fos. The percentage of c-Fos-positive oxytocin cells in the hypothalamic paraventricular nucleus was significantly lower in rats chronically exposed to the HS than to the CS diet, regardless of which diet they received on the final day. A similar pattern was observed in the supraoptic nucleus. We conclude that the chronic rather than acute sucrose intake reduces activity of the anorexigenic oxytocin system. These findings indicate that chronic consumption of sugar blunts activity of pathways that mediate satiety. We speculate that a reduction in central satiety signaling precipitated by regular intake of foods high in sugar may lead to generalized overeating.
authors.affiliation: Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave., St. Paul, MN 55108, USA. amitra@umn.edu
authors.forename: Anaya
authors.initials: A
authors.lastname: Mitra
authors.forename: Blake A
authors.initials: BA
authors.lastname: Gosnell
authors.forename: Helgi B
authors.initials: HB
authors.lastname: Schiöth
authors.forename: Martha K
authors.initials: MK
authors.lastname: Grace
authors.forename: Anica
authors.initials: A
authors.lastname: Klockars
authors.forename: Pawel K
authors.initials: PK
authors.lastname: Olszewski
authors.forename: Allen S
authors.initials: AS
authors.lastname: Levine
mesh_terms: D000818:Animals; D019422:Dietary Sucrose / Q000008:administration & dosage*; D005518:Food Preferences; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000378:metabolism*; D010121:Oxytocin / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012527:Satiation / Q000502:physiology*
chemical_list: D019422:Dietary Sucrose; D010121:Oxytocin
references.citation: Peptides. 2009 Feb;30(2):226-33
references.pmid: 19022308
references.citation: Physiol Behav. 1997 Aug;62(2):347-52
references.pmid: 9251978
references.citation: Am J Physiol Regul Integr Comp Physiol. 2000 Oct;279(4):R1504-11
references.pmid: 11004021
references.citation: Peptides. 1991 Jan-Feb;12(1):113-8
references.pmid: 1646995
references.citation: J Physiol. 1997 Nov 15;505 ( Pt 1):145-52
references.pmid: 9409478
references.citation: J Physiol. 1990 Sep;428:95-108
references.pmid: 2231433
references.citation: Physiol Behav. 1990 Dec;48(6):825-30
references.pmid: 2087513
references.citation: Peptides. 1989 Jan-Feb;10(1):89-93
references.pmid: 2748428
references.citation: Brain Res Rev. 2010 Mar;62(2):147-64
references.pmid: 19931559
references.citation: Endocrinology. 2004 Jun;145(6):2627-32
references.pmid: 15044361
references.citation: J Neurosci. 2008 Oct 8;28(41):10272-7
references.pmid: 18842886
references.citation: Brain Res. 1983 Jun 27;270(1):169-73
references.pmid: 6191839
references.citation: Am J Clin Nutr. 2004 Mar;79(3):372-8
references.pmid: 14985209
references.citation: Physiol Behav. 2007 Aug 15;91(5):506-12
references.pmid: 17316713
references.citation: Psychopharmacology (Berl). 2002 Feb;159(4):415-23
references.pmid: 11823894
references.citation: Am J Physiol Regul Integr Comp Physiol. 2000 Mar;278(3):R732-40
references.pmid: 10712295
references.citation: Am J Physiol Regul Integr Comp Physiol. 2004 Jul;287(1):R87-96
references.pmid: 15044184
references.citation: Am J Physiol Regul Integr Comp Physiol. 2007 Sep;293(3):R1063-8
references.pmid: 17596329
references.citation: J Histochem Cytochem. 1980 Apr;28(4):357-60
references.pmid: 6989899
references.citation: Am J Clin Nutr. 2006 Aug;84(2):274-88
references.pmid: 16895873
references.citation: Pharmacol Biochem Behav. 1991 Sep;40(1):27-32
references.pmid: 1780342
references.citation: Int J Obes (Lond). 2009 Jun;33 Suppl 2:S54-8
references.pmid: 19528981
references.citation: Pharmacol Biochem Behav. 1979 Oct;11(4):391-4
references.pmid: 523497
references.citation: Stress. 2004 Jun;7(2):97-107
references.pmid: 15512853
references.citation: Chem Senses. 2007 Jan;32(1):99-103
references.pmid: 17110527
references.citation: Brain Res Mol Brain Res. 2004 May 19;124(2):134-42
references.pmid: 15135221
references.citation: J Endocrinol. 1985 Dec;107(3):437-46
references.pmid: 2999285
references.citation: Am J Physiol Regul Integr Comp Physiol. 2007 May;292(5):R1828-33
references.pmid: 17272659
references.citation: Am J Physiol Regul Integr Comp Physiol. 2005 Dec;289(6):R1798-806
references.pmid: 16150836
references.citation: Nat Rev Neurosci. 2004 Mar;5(3):209-17
references.pmid: 14976520
references.citation: Proc Natl Acad Sci U S A. 2009 Jul 28;106(30):12512-7
references.pmid: 19597155
references.citation: Brain Res. 2001 Apr 13;898(1):162-5
references.pmid: 11292460
references.citation: Am J Physiol Regul Integr Comp Physiol. 2004 Jan;286(1):R31-7
references.pmid: 12933362
references.citation: Behav Brain Res. 2006 Jul 15;171(1):134-41
references.pmid: 16677726
references.citation: Am J Physiol Regul Integr Comp Physiol. 2005 Jan;288(1):R292-300
references.pmid: 15358606
references.citation: Physiol Behav. 2009 Mar 23;96(4-5):568-73
references.pmid: 19136019
references.citation: J Neurosci. 2006 Sep 6;26(36):9196-204
references.pmid: 16957076
references.citation: Ann N Y Acad Sci. 2009 Jul;1170:347-64
references.pmid: 19686159
references.citation: Endocrinology. 1991 Aug;129(2):785-91
references.pmid: 1649746
references.citation: Brain Res Bull. 1991 Sep-Oct;27(3-4):383-6
references.pmid: 1959034
references.citation: Neurosci Biobehav Rev. 1987 Summer;11(2):215-22
references.pmid: 3614789