Hepatic-Portal Vein Infusions of Glucagon-Like Peptide-1 Reduce Meal Size and Increase c-Fos Expression in the Nucleus Tractus Solitarii, Area Postrema and Central Nucleus of the Amygdala in Rats

• Published in: Journal of neuroendocrinology Vol. 22; no. 6; pp. 557 - 563
• Main Authors: Baumgartner, I., Pacheco-López, G., Rüttimann, E. B., Arnold, M., Asarian, L ., Langhans, W., Geary, N., Hillebrand, J. J. G.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.06.2010; Blackwell
• Subjects: Amygdala - drug effects; Amygdala - metabolism; Animals; Area Postrema - drug effects; Area Postrema - metabolism; aversion; Biological and medical sciences; Cerebral circulation. Blood-brain barrier. Choroid plexus. Cerebrospinal fluid. Circumventricular organ. Meninges; eating; Feeding Behavior - drug effects; Fundamental and applied biological sciences. Psychology; Glucagon-Like Peptide 1 - administration & dosage; Glucagon-Like Peptide 1 - pharmacology; gut peptide; hindbrain; Immunohistochemistry; Male; Portal Vein; Proto-Oncogene Proteins c-fos - metabolism; Rats; Rats, Sprague-Dawley; satiation; Solitary Nucleus - drug effects; Solitary Nucleus - metabolism; Vertebrates: endocrinology; Vertebrates: nervous system and sense organs; Amygdala; Rat; Size; Central nervous system; Meal; gut peptide; hindbrain; satiation; Encephalon; aversion; Gastrointestinal hormone; Area postrema; Protooncogene; Ependymal organ; Digestive system; fos Gene; Rodentia; Gut; Basal ganglion; Gene expression; eating; Glucagon like peptide 1; Solitary nucleus; Vertebrata; Mammalia; Animal; Portal vein; Immediate early gene
• ISSN: 0953-8194; 1365-2826
• DOI: 10.1111/j.1365-2826.2010.01995.x

We recently reported that brief, remotely controlled intrameal hepatic‐portal vein infusions of glucagon‐like peptide‐1 (GLP‐1) reduced spontaneous meal size in rats. To investigate the neurobehavioural correlates of this effect, we equipped male Sprague‐Dawley rats with hepatic‐portal vein catheters and assessed (i) the effect on eating of remotely triggered infusions of GLP‐1 (1 nmol/kg, 5 min) or vehicle during the first nocturnal meal after 3 h of food deprivation and (ii) the effect of identical infusions performed at dark onset on c‐Fos expression in several brain areas involved in the control of eating. GLP‐1 reduced (P < 0.05) the size of the first nocturnal meal and increased its satiety ratio. Also, GLP‐1 increased (P < 0.05) the number of c‐Fos‐expressing cells in the nucleus tractus solitarii, the area postrema and the central nucleus of the amygdala, but not in the arcuate or paraventricular hypothalamic nuclei. These data suggest that the nucleus tractus solitarii, the area postrema and the central nucleus of the amygdala play a role in the eating‐inhibitory actions of GLP‐1 infused into the hepatic‐portal vein; it remains to be established whether activation of these brain nuclei reflect satiation, aversion, or both.