scholarly journals NPY2 receptor activation in the dorsal vagal complex increases food intake and attenuates CCK-induced satiation in male rats

2019 ◽  
Vol 316 (4) ◽  
pp. R406-R416
Author(s):  
Nathaneal J. Huston ◽  
Lynne A. Brenner ◽  
Zachary C. Taylor ◽  
Robert C. Ritter
Keyword(s):  
Food Intake ◽  
Peptide Yy ◽  
Receptor Activation ◽  
Vagal Afferents ◽  
Male Rats ◽  
Dorsal Vagal Complex ◽  
Increase Food Intake ◽  
Control Food ◽  
Intracerebroventricular Injections ◽  
Control Food Intake

Neuropeptide Y (NPY), peptide YY (PYY), and their cognate receptors (YR) are expressed by subpopulations of central and peripheral nervous system neurons. Intracerebroventricular injections of NPY or PYY increase food intake, and intrahypothalamic NPY1 or NPY5 receptor agonist injections also increase food intake. In contrast, injection of PYY in the periphery reduces food intake, apparently by activating peripheral Y2R. The dorsal vagal complex (DVC) of the hindbrain is the site where vagal afferents relay gut satiation signals to the brain. While contributions of the DVC are increasingly investigated, a role for DVC YR in control of food intake has not been examined systematically. We used in situ hybridization to confirm expression of Y1R and Y2R, but not Y5R, in the DVC and vagal afferent neurons. We found that nanoinjections of a Y2R agonist, PYY-(3–36), into the DVC significantly increased food intake over a 4-h period in satiated male rats. PYY-(3–36)-evoked food intake was prevented by injection of a selective Y2R antagonist. Injection of a Y1R/Y5R-preferring agonist into the DVC failed to increase food intake at doses reported to increase food intake following hypothalamic injection. Finally, injection of PYY-(3–36) into the DVC prevented reduction of 30-min food intake following intraperitoneal injection of cholecystokinin (CCK). Our results indicate that activation of DVC Y2R, unlike hypothalamic or peripheral Y2R, increases food intake. Furthermore, in the context of available electrophysiological observations, our results are consistent with the hypothesis that DVC Y2R control food intake by dampening vagally mediated satiation signals in the DVC.

scholarly journals Peptide YY, appetite and food intake

2005 ◽  
Vol 64 (2) ◽  
pp. 213-216 ◽  
Author(s):  
C. W. le Roux ◽  
S. R. Bloom
Keyword(s):  
Food Intake ◽  
Peptide Yy ◽  
Energy Content ◽  
Peak Plasma ◽  
Evolutionary Relationship ◽  
Gut Hormones ◽  
Amino Acid Peptide ◽  
Control Food ◽  
Glucagon Like Peptide 1 ◽  
Control Food Intake

Obesity is taking on pandemic proportions. The laws of thermodynamics, however, remain unchanged, as energy will be stored if less energy is expended than consumed; the storage is usually in the form of adipose tissue. Several neural, humeral and psychological factors control the complex process known as appetite. Recently, a close evolutionary relationship between the gut and brain has become apparent. The gut hormones regulate important gastrointestinal functions such as motility, secretion, absorption, provide feedback to the central nervous system on availability of nutrients and may play a part in regulating food intake. Peptide YY (PYY) is a thirty-six amino acid peptide related to neuropeptide Y (NPY) and is co-secreted with glucagon-like peptide 1. Produced by the intestinal L-cells, the highest tissue concentrations of PYY are found in distal segments of the gastrointestinal tract, although it is present throughout the gut. Following food intake PYY is released into the circulation. PYY concentrations are proportional to meal energy content and peak plasma levels appear postprandially after 1 h. PYY3-36 is a major form of PYY in both the gut mucosal endocrine cells and the circulation. Peripheral administration of PYY3-36 inhibits food intake for several hours in both rodents and man. The binding of PYY3-36 to the Y2 receptor leads to an inhibition of the NPY neurones and a possible reciprocal stimulation of the pro-opiomelanocortin neurones. Thus, PYY3-36 appears to control food intake by providing a powerful feedback on the hypothalamic circuits. The effect on food intake has been demonstrated at physiological concentrations and, therefore, PYY3-36 may be important in the everyday regulation of food intake.

Vagal afferents are not necessary for the satiety effect of the gut lipid messenger oleoylethanolamide

2014 ◽  
Vol 307 (2) ◽  
pp. R167-R178 ◽  
Author(s):  
Elnaz Karimian Azari ◽  
Deepti Ramachandran ◽  
Sandra Weibel ◽  
Myrtha Arnold ◽  
Adele Romano ◽  
...  
Keyword(s):  
Food Intake ◽  
Peptide Yy ◽  
Vena Cava ◽  
Diet Group ◽  
Vagal Afferents ◽  
Male Rats ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Gut Peptides ◽  
Nonesterified Fatty Acids

The endogenous lipid messenger oleoylethanolamide (OEA) inhibits eating and modulates fat metabolism supposedly through the activation of peroxisome proliferator-activated receptor-α (PPARα) and vagal sensory fibers. We tested in adult male rats whether OEA stimulates fatty acid oxidation (FAO) and ketogenesis and whether it increases plasma levels of the satiating gut peptides glucagon-like peptide-1 (GLP-1) and peptide YY (PYY). We also explored whether OEA still inhibits eating after subdiaphragmatic vagal deafferentation (SDA). We found that intraperitoneally injected OEA (10 mg/kg body wt) reduced ( P < 0.05) food intake mainly by increasing meal latency and that this effect was stronger in rats fed a 60% high-fat diet (HFD) than in chow-fed rats. OEA increased ( P < 0.05) postprandial plasma nonesterified fatty acids and β-hydroxybutyrate (BHB) in the hepatic portal vein (HPV) and vena cava (VC) 30 min after injection, which was more pronounced in HFD- than in chow-fed rats. OEA also increased the protein expression of the key ketogenetic enzyme, mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase, in the jejunum of HFD-fed rats, but not in the liver or duodenum of either diet group. Furthermore, OEA decreased GLP-1 and PYY concentrations ( P < 0.05) in the HPV and VC 30 min after administration. Finally, OEA reduced food intake in SDA and sham-operated rats similarly. Our findings indicate that neither intact abdominal vagal afferents nor prandial increases in GLP-1 or PYY are necessary for the satiety effect of OEA. The enhanced FAO and ketogenesis raise the possibility of an involvement of intestine-derived BHB in OEA's satiety effect under certain conditions.

scholarly journals Obesity and Appetite Control

2012 ◽  
Vol 2012 ◽  
pp. 1-19 ◽  
Author(s):  
Keisuke Suzuki ◽  
Channa N. Jayasena ◽  
Stephen R. Bloom
Keyword(s):  
Food Intake ◽  
Energy Homeostasis ◽  
Peptide Yy ◽  
Gut Hormones ◽  
Appetite Control ◽  
Control Food ◽  
Adiposity Signals ◽  
Term Energy ◽  
Glucagon Like Peptide 1 ◽  
Control Food Intake

Obesity is one of the major challenges to human health worldwide; however, there are currently no effective pharmacological interventions for obesity. Recent studies have improved our understanding of energy homeostasis by identifying sophisticated neurohumoral networks which convey signals between the brain and gut in order to control food intake. The hypothalamus is a key region which possesses reciprocal connections between the higher cortical centres such as reward-related limbic pathways, and the brainstem. Furthermore, the hypothalamus integrates a number of peripheral signals which modulate food intake and energy expenditure. Gut hormones, such as peptide YY, pancreatic polypeptide, glucagon-like peptide-1, oxyntomodulin, and ghrelin, are modulated by acute food ingestion. In contrast, adiposity signals such as leptin and insulin are implicated in both short- and long-term energy homeostasis. In this paper, we focus on the role of gut hormones and their related neuronal networks (the gut-brain axis) in appetite control, and their potentials as novel therapies for obesity.

Effect of a protein preload on food intake and satiety feelings in response to duodenal fat perfusions in healthy male subjects

2005 ◽  
Vol 289 (4) ◽  
pp. R1042-R1047 ◽  
Author(s):  
Sibylle Oesch ◽  
Lukas Degen ◽  
Christoph Beglinger
Keyword(s):  
Food Intake ◽  
Synergistic Effect ◽  
Peptide Yy ◽  
Caloric Intake ◽  
Healthy Male ◽  
Double Blind ◽  
Control Food ◽  
Initial Hypothesis ◽  
Glucagon Like Peptide 1 ◽  
Control Food Intake

The control of food intake and satiety requires a coordinated interplay. Oral protein and duodenal fat inhibit food intake and induce satiety, but their interactive potential is unclear. Our aim was therefore to investigate the interactions between an oral protein preload and intraduodenal (ID) fat on food intake and satiety feelings. Twenty healthy male volunteers were studied in a randomized, double-blind, four-period crossover design. On each study day, subjects underwent one of the following treatments: 1) water preload plus ID saline perfusion, 2) water preload plus ID fat perfusion, 3) protein preload plus ID saline perfusion, or 4) protein preload plus ID fat perfusion. Subjects were free to eat and drink as much as they wished. An oral protein preload significantly reduced caloric intake (19%, P < 0.01). Simultaneous administration of an oral protein preload and ID fat did not result in a positive synergistic effect with respect to caloric consumption, rejecting the initial hypothesis that the two nutrients exert a positive synergistic effect on food intake. An oral protein preload but not ID fat altered the feelings of hunger and fullness. These data indicate that the satiety effect of an oral protein preload is not amplified by ID fat; indeed, the effect of a protein preload does not seem to be mediated by cholecystokinin, glucagon-like peptide-1, or peptide YY. Much more information is necessary to understand the basic physiological mechanisms that control food intake and satiety.

Parenteral nutrition, brain glycogen, and food intake

1993 ◽  
Vol 265 (6) ◽  
pp. R1387-R1391
Author(s):  
M. M. Meguid ◽  
J. L. Beverly ◽  
Z. J. Yang ◽  
J. R. Gleason ◽  
R. A. Meguid ◽  
...  
Keyword(s):  
Food Intake ◽  
Parenteral Nutrition ◽  
Plasma Glucose ◽  
Glycogen Content ◽  
Fischer 344 Rats ◽  
Brain Glycogen ◽  
Fischer 344 ◽  
Control Food ◽  
Control Food Intake ◽  
Infusion Period

To determine whether brain glycogen concentrations change during parenteral nutrition, Fischer 344 rats with jugular vein catheters received 0.9 N saline or parenteral nutrition providing 100% of daily calories (PN-100). Rats were killed after 4 days of PN-100 and serially after PN-100 was stopped. Food intake decreased during PN-100 to approximately 15% of control, but total kilocalories eaten and infused over the 4-day PN-100 period was approximately 130% of control. Food intake of PN-100 rats remained low for 3-4 days post-PN-100. At the end of the 4-day PN-100 period, plasma glucose and insulin (P = 0.01) and whole brain glycogen (P < 0.005) were higher than but similar to control within 24 h of PN-100 being stopped. When PN-100 rats were not allowed to eat during the infusion period, plasma glucose was lower, plasma insulin higher, and brain glycogen content the same as in control rats after 4 days of PN-100. The increased brain glycogen was the likely consequence of the hyperglycemia and hyperinsulinemia during PN-100 and was not causally associated with the reduced food intake either during or immediately after PN-100.

scholarly journals CCK-Induced Reduction of Food Intake and Hindbrain MAPK Signaling Are Mediated by NMDA Receptor Activation

Endocrinology ◽  
2012 ◽  
Vol 153 (6) ◽  
pp. 2633-2646 ◽  
Author(s):  
Carlos A. Campos ◽  
Jason S. Wright ◽  
Krzysztof Czaja ◽  
Robert C. Ritter
Keyword(s):  
Nmda Receptor ◽  
Food Intake ◽  
Nmda Receptors ◽  
Receptor Antagonist ◽  
Fourth Ventricle ◽  
Receptor Activation ◽  
Nmda Receptor Antagonist ◽  
Vagal Afferents ◽  
Mapk Kinase ◽  
Vagal Afferent

The dorsal vagal complex of the hindbrain, including the nucleus of the solitary tract (NTS), receives neural and humoral afferents that contribute to the process of satiation. The gut peptide, cholecystokinin (CCK), promotes satiation by activating gastrointestinal vagal afferents that synapse in the NTS. Previously, we demonstrated that hindbrain administration of N-methyl-d-aspartate (NMDA)-type glutamate receptor antagonists attenuate reduction of food intake after ip CCK-8 injection, indicating that these receptors play a necessary role in control of food intake by CCK. However, the signaling pathways through which hindbrain NMDA receptors contribute to CCK-induced reduction of food intake have not been investigated. Here we report CCK increases phospho-ERK1/2 in NTS neurons and in identified vagal afferent endings in the NTS. CCK-evoked phospho-ERK1/2 in the NTS was attenuated in rats pretreated with capsaicin and was abolished by systemic injection of a CCK1 receptor antagonist, indicating that phosphorylation of ERK1/2 occurs in and is mediated by gastrointestinal vagal afferents. Fourth ventricle injection of a competitive NMDA receptor antagonist, prevented CCK-induced phosphorylation of ERK1/2 in hindbrain neurons and in vagal afferent endings, as did direct inhibition of MAPK kinase. Finally, fourth ventricle administration of either a MAPK kinase inhibitor or NMDA receptor antagonist prevented the reduction of food intake by CCK. We conclude that activation of NMDA receptors in the hindbrain is necessary for CCK-induced ERK1/2 phosphorylation in the NTS and consequent reduction of food intake.

scholarly journals TOXIC EFFECTS OF LARGE DOSE OF QUASSIN IN NORMAL AND DEPRIVED MICROFLORA RAT GROUPS

2021 ◽  
Vol 22 (1) ◽  
pp. 67-83
Author(s):  
Duraid A.Abbas ◽  
O.M.S. Al—Shaha,
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Water Intake ◽  
Daily Food ◽  
Daily Water Intake ◽  
Control Food ◽  
Liver And Kidney ◽  
Daily Water ◽  
Control Food Intake ◽  
Intake Water

Eighteen rats were divided into three equal groups. The first group was closed orally with quassin, the second group was dosed with quassin after the gut flora were suppressed by difierent antibiotics, and the third group was served as a control. Food intake, water intake, and change in body weight were measured daily before dosing, during two weeks of dosing, and during one week after stopping dosing. Two eats from each group were killed at the end of each week, and stomach, liver, and kidney were collected for histopathologic examination. The results show a significant decline in daily food intake and daily change in body weight, and a significant increase in daily water intake in both dosed groups during the dosing period. Microscopic lesions were seen in the kidneys of both dosed rats group killed at the end of first and second week

PYY(3–36) reduces food intake and body weight and improves insulin sensitivity in rodent models of diet-induced obesity

2006 ◽  
Vol 291 (2) ◽  
pp. R367-R375 ◽  
Author(s):  
Niels Vrang ◽  
Andreas Nygaard Madsen ◽  
Mads Tang-Christensen ◽  
Gitte Hansen ◽  
Philip Just Larsen
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Peptide Yy ◽  
Body Weight Gain ◽  
Subcutaneous Administration ◽  
Treated Group ◽  
Metabolic Effects ◽  
Male Rats ◽  
Reduced Body ◽  
Gut Hormone

The gut hormone peptide YY (PYY) was recently proposed to comprise an endogenous satiety factor. We have studied acute anorectic functions of PYY(3–36) in mice and rats, as well as metabolic effects of chronic PYY(3–36) administration to diet-induced obese (DIO) mice and rats. A single intraperitoneal injection of PYY(3–36) inhibited food intake in mice, but not in rats. We next investigated the effects of increasing doses (100, 300, and 1,000 μg·kg−1·day−1) of PYY(3–36) administered subcutaneously via osmotic minipumps on food intake and body weight in DIO C57BL/6J mice. Whereas only the highest dose (1,000 μg·kg−1·day−1) of PYY(3–36) significantly reduced food intake over the first 3 days, body weight gain was dose dependently reduced, and on day 28 the group treated with 1,000 μg·kg−1·day−1 PYY(3–36) weighed ∼10% less than the vehicle-treated group. Mesenteric, epididymal, retroperitoneal, and inguinal fat pad weight was dose dependently reduced. Subcutaneous administration of PYY(3–36) (250 and 1,000 μg·kg−1·day−1) for 28 days reduced body weight and improved glycemic control in glucose-intolerant DIO rats. Neither 250 nor 1,000 μg/kg PYY(3–36) elicited a conditioned taste aversion in male rats.

Sign in / Sign up

Export Citation Format

Share Document