scholarly journals Involvement of Apolipoprotein A-IV and Cholecystokinin1 Receptors in Exogenous Peptide YY3–36-Induced Stimulation of Intestinal Feedback

Endocrinology ◽  
2007 ◽  
Vol 148 (10) ◽  
pp. 4695-4703 ◽  
Author(s):  
K. L. Whited ◽  
P. Tso ◽  
H. E. Raybould
Keyword(s):  
Gastric Emptying ◽  
Food Intake ◽  
Peptide Yy ◽  
Immunohistochemical Localization ◽  
Receptor Blockade ◽  
Wild Type ◽  
Apolipoprotein A ◽  
Fos Protein ◽  
Stimulation Of

Peptide YY (PYY)3–36, released by intestinal lipid elicits functional effects that comprise the intestinal feedback response to luminal nutrients, but the pathway of action is not fully characterized. The aim of the present study was to determine the role of the apolipoprotein (apo) A-IV-cholecystokinin (CCK)1 receptor (CCK1R) pathway in exogenous PYY3–36-induced activation of the gut-brain axis and inhibition of gastric emptying and food intake. PYY3–36 (5 μg/100 g ip) significantly inhibited gastric emptying of a chow meal in wild-type but not A-IV−/− mice andCCK1R receptor blockade with devazepide (10 μg/100 g), abolished PYY3–36-induced inhibition of gastric emptying. PYY3–36-induced inhibition of food intake in both ad libitum-fed and 16-h fasted mice was unaltered in A-IV−/− mice, compared with wild-type controls, or by CCK1R receptor blockade with devazepide. PYY3–36 activated neurons in the midregion of the nucleus of the solitary tract (bregma −7.32 to −7.76 mm) in A-IV+/+ mice; this was measured by immunohistochemical localization of Fos protein. PYY3–36-induced Fos expression was significantly reduced by 65% in A-IV+/+ mice pretreated systemically with the sensory neurotoxin capsaicin (5 mg/100 g), 78% by the CCK1R antagonist, devazepide (10 μg/100 g), and 39% by the Y2R antagonist, BIIE0246 (200 and 600 μg/100 g) and decreased by 67% in apo A-IV−/− mice, compared with A-IV+/+ controls. The data suggest a role for apo A-IV and the CCK1R in PYY3–36-induced activation of the vagal afferent pathway and inhibition of gastric emptying, but this is likely not the pathway mediating the effects of PYY3–36 on food intake.

Roux-en-Y Gastrointestinal Bypass Promotes Activation of TGR5 and Peptide YY

2020 ◽  
Vol 20 (8) ◽  
pp. 1262-1267
Author(s):  
Haojun Yang ◽  
Hanyang Liu ◽  
YuWen Jiao ◽  
Jun Qian
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Metabolic Diseases ◽  
Peptide Yy ◽  
The Body ◽  
Wild Type ◽  
L Cells ◽  
Body Weights ◽  
Gastrointestinal Bypass ◽  
G Protein Coupled

Background: G protein-coupled bile acid receptor (TGR5) is involved in a number of metabolic diseases. The aim of this study was to identify the role of TGR5 after Roux-en-Y gastric bypass (GBP). Methods: Wild type and TGR5 knockout mice (tgr5-/-) were fed a high-fat diet (HFD) to establish the obesity model. GBP was performed. The changes in body weight and food intake were measured. The levels of TGR5 and peptide YY (PYY) were evaluated by RT-PCR, Western blot, and ELISA. Moreover, the L-cells were separated from wild type and tgr5-/- mice. The levels of PYY in L-cells were evaluated by ELISA. Results: The body weights were significantly decreased after GBP in wild type mice (p<0.05), but not tgr5-/- mice (p>0.05). Food intake was reduced after GBP in wild type mice, but also not significantly affected in tgr5-/- mice (p>0.05). The levels of PYY were significantly increased after GBP compared with the sham group (p<0.05); however, in tgr5-/- mice the expression of PYY was not significantly affected (p>0.05). After INT-777 stimulation in L-cells obtained from murine intestines, the levels of PYY were significantly increased in L-cells tgr5+/+ (p<0.05). Conclusion: Our study suggests that GBP up-regulated the expression of TGR5 in murine intestines, and increased the levels of PYY, which further reduced food intake and decreased the body weight.

scholarly journals Gastric Sensory and Motor Functions and Energy Intake in Health and Obesity—Therapeutic Implications

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1158
Author(s):  
Lizeth Cifuentes ◽  
Michael Camilleri ◽  
Andres Acosta
Keyword(s):  
Energy Consumption ◽  
Gastric Emptying ◽  
Food Intake ◽  
Gastric Volume ◽  
Obesity Management ◽  
Bariatric Endoscopy ◽  
Motor Functions ◽  
Therapeutic Implications ◽  
Intestinal Functions

Sensory and motor functions of the stomach, including gastric emptying and accommodation, have significant effects on energy consumption and appetite. Obesity is characterized by energy imbalance; altered gastric functions, such as rapid gastric emptying and large fasting gastric volume in obesity, may result in increased food intake prior to reaching usual fullness and increased appetite. Thus, many different interventions for obesity, including different diets, anti-obesity medications, bariatric endoscopy, and surgery, alter gastric functions and gastrointestinal motility. In this review, we focus on the role of the gastric and intestinal functions in food intake, pathophysiology of obesity, and obesity management.

LPS inhibits fasted plasma ghrelin levels in rats: role of IL-1 and PGs and functional implications

2006 ◽  
Vol 291 (4) ◽  
pp. G611-G620 ◽  
Author(s):  
Lixin Wang ◽  
Nicole R. Basa ◽  
Almaas Shaikh ◽  
Andrew Luckey ◽  
David Heber ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Gastric Emptying ◽  
Food Intake ◽  
Intravenous Injection ◽  
Plasma Levels ◽  
Inhibitory Action ◽  
Functional Implications ◽  
Urocortin 1 ◽  
Fasted Rats

LPS injected intraperitoneally decreases fasted plasma levels of ghrelin at 3 h postinjection in rats. We characterized the inhibitory action of LPS on plasma ghrelin and whether exogenous ghrelin restores LPS-induced suppression of food intake and gastric emptying in fasted rats. Plasma ghrelin and insulin and blood glucose were measured after intraperitoneal injection of LPS, intravenous injection of IL-1β and urocortin 1, and in response to LPS under conditions of blockade of IL-1 or CRF receptors by subcutaneous injection of IL-1 receptor antagonist (IL-1Ra) or astressin B, respectively, and prostaglandin (PG) synthesis by intraperitoneal indomethacin. Food intake and gastric emptying were measured after intravenous injection of ghrelin at 5 h postintraperitoneal LPS injection. LPS inhibited the elevated fasted plasma ghrelin levels by 47.6 ± 4.9%, 58.9 ± 3.3%, 74.4 ± 2.7%, and 48.9 ± 8.7% at 2, 3, 5, and 7 h postinjection, respectively, and values returned to preinjection levels at 24 h. Insulin levels were negatively correlated to those of ghrelin, whereas there was no significant correlation between glucose and ghrelin. IL-1Ra and indomethacin prevented the first 3-h decline in ghrelin levels induced by LPS, whereas astressin B did not. IL-1β inhibited plasma ghrelin levels, whereas urocortin 1 had no influence. Ghrelin injected intravenously prevented an LPS-induced 87% reduction of gastric emptying and 61% reduction of food intake. These data showed that IL-1 and PG pathways are part of the early mechanisms by which LPS suppresses fasted plasma ghrelin and that exogenous ghrelin can normalize LPS-induced-altered digestive functions.

Vagal control of pyloric resistance

1995 ◽  
Vol 269 (4) ◽  
pp. G558-G569 ◽  
Author(s):  
C. H. Malbert ◽  
C. Mathis ◽  
J. P. Laplace
Keyword(s):  
Gastric Emptying ◽  
Temporal Relationship ◽  
Vagal Stimulation ◽  
Simultaneous Recording ◽  
Nervous Control ◽  
Transpyloric Flow ◽  
Cervical Vagotomy ◽  
Vagal Efferents ◽  
Stimulation Of

Pyloric resistance is probably a major factor regulating gastric emptying of liquids, but its nervous control is unknown. The role of efferent vagal pathways in pyloric resistance was evaluated in 13 anesthetized pigs. Pyloric resistance was assessed by simultaneous recording of gastropyloroduodenal motility and transpyloric flow during gastric emptying of saline. Cervical vagotomy suppressed all antral pressure events, increased the number of pressure events localized at the pylorus, and decreased the frequency of the flow pulses (P < 0.05), without affecting either pyloric resistance or the characteristics of flow pulses. Electrical stimulation of the cervical and the thoracic vagi both decreased pyloric resistance by about 60% and increased the stroke volume of flow pulses (P < 0.05). The reduced pyloric resistance was mainly related to an alteration of the temporal relationship between flow pulses and pyloric pressure events. These results indicate that vagal efferents could provide inhibitory inputs to pyloric resistance. A reduction in pyloric resistance contributes to the increased flow rate observed during vagal stimulation.

Effect of food intake on intestinal cholesterol synthesis in rats

1986 ◽  
Vol 251 (3) ◽  
pp. G362-G369
Author(s):  
K. R. Feingold ◽  
G. Zsigmond ◽  
S. R. Lear ◽  
A. H. Moser
Keyword(s):  
Small Intestine ◽  
Food Intake ◽  
Direct Contact ◽  
Cholesterol Synthesis ◽  
Third Trimester ◽  
Increase Food Intake ◽  
Effect Of Food ◽  
Small Intestinal ◽  
Stimulation Of

The mechanism by which diabetes results in an increase in small intestinal cholesterol synthesis is unknown. Previous studies have demonstrated that limiting food intake prevents the increase in intestinal cholesterol synthesis, and it has therefore been proposed that the stimulation of cholesterol synthesis in the small intestine is secondary to the hyperphagia that is associated with poorly controlled diabetes. To shed further light on the role of hyperphagia we have studied the effect on cholesterol synthesis of a variety of conditions that increase food intake. In third-trimester pregnant animals, lactating animals, obese animals, and in animals infused intragastrically with 16 g glucose/day vs. 8 g glucose/day, we have observed that an increase in food intake is associated with an increase in small intestinal cholesterol synthesis. Furthermore, these findings support the hypothesis that hyperphagia is the chief stimulus for the increase in cholesterol synthesis in the small intestine of diabetic animals. Additional studies have demonstrated that simply increasing the bulk of food ingested by adding Alphacel to the diet does not alter cholesterol synthesis in the small intestine. Lastly, in animals in whom Thiry fistulas were surgically constructed we observed that cholesterol synthesis is increased in the diabetic animals in both the segment of the small intestine in contact with the food stream and the segment of the small intestine that is excluded from contact. This observation suggests that the direct contact of the intestinal mucosa with caloric sources is not the sole trigger for increasing small intestinal cholesterol synthesis in hyperphagic diabetic animals.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Neutralization or Absence of the Interleukin-23 Pathway Does Not Compromise Immunity to Mycobacterial Infection

2006 ◽  
Vol 74 (11) ◽  
pp. 6092-6099 ◽  
Author(s):  
Alissa A. Chackerian ◽  
Shi-Juan Chen ◽  
Scott J. Brodie ◽  
Jeanine D. Mattson ◽  
Terrill K. McClanahan ◽  
...  
Keyword(s):  
Immune Response ◽  
Secondary Infection ◽  
Mycobacterial Infection ◽  
Effective Control ◽  
Bacterial Burden ◽  
Wild Type ◽  
Interleukin 23 ◽  
Deficient Mice ◽  
Stimulation Of

ABSTRACT Interleukin-23 (IL-23), a member of the IL-12 family, is a heterodimeric cytokine that is composed of the p40 subunit of IL-12 plus a unique p19 subunit. IL-23 is critical for autoimmune inflammation, in part due to its stimulation of the proinflammatory cytokine IL-17A. It is less clear, however, if IL-23 is required during the immune response to pathogens. We examined the role of IL-23 during Mycobacterium bovis BCG infection. We found that IL-23 reduces the bacterial burden and promotes granuloma formation when IL-12 is absent. However, IL-23 does not contribute substantially to host resistance when IL-12 is present, as the ability to control bacterial growth and form granulomata is not affected in IL-23p19-deficient mice and mice treated with a specific anti-IL-23p19 antibody. IL-23p19-deficient mice are also able to mount an effective memory response to secondary infection with BCG. While IL-23p19-deficient mice do not produce IL-17A, this cytokine is not necessary for effective control of infection, and antibody blocking of IL-17A in both wild-type and IL-12-deficient mice also has little effect on the bacterial burden. These data suggest that IL-23 by itself does not play an essential role in the protective immune response to BCG infection; however, the presence of IL-23 can partially compensate for the absence of IL-12. Furthermore, neutralization of IL-23 or IL-17A does not increase susceptibility to mycobacterial BCG infection.

NMDA receptor blockade attenuates CCK-induced reduction of real feeding but not sham feeding

2004 ◽  
Vol 286 (5) ◽  
pp. R826-R831 ◽  
Author(s):  
Mihai Covasa ◽  
Robert C. Ritter ◽  
Gilbert A. Burns
Keyword(s):  
Gastric Emptying ◽  
Ion Channels ◽  
Nmda Receptor ◽  
Food Intake ◽  
Receptor Blockade ◽  
Sham Feeding ◽  
Systemic Injection ◽  
Mk 801 ◽  
Nmda Receptor Blockade ◽  
Series Of Experiments

Systemic injection of MK-801, a noncompetitive antagonist of N-methyl-d-aspartate (NMDA) receptor ion channels, increases meal size and delays satiation. We examined whether MK-801 increases food intake by directly interfering with actions of cholecystokinin (CCK). Prior administration of MK-801 (100 μg/kg ip) reversed the inhibitory effects of CCK-8 (2 and 4 μg/kg ip) on real feeding of both liquid and solid foods. MK-801 alone did not alter 30-min sham intake of 15% sucrose compared with intake after saline. Furthermore, while CCK-8 (2 or 4 μg/kg ip) reduced sham intake, this reduction was not attenuated by MK-801 pretreatment. To ascertain whether MK-801 attenuation of CCK-induced reduction of real feeding was associated with attenuated inhibition of gastric emptying, we tested the effect of MK-801 pretreatment on CCK-induced inhibition of gastric emptying of 5-ml saline loads. Ten-minute gastric emptying was accelerated after MK-801 (3.9 ± 0.2 ml) compared with saline vehicle (2.72 ± 0.2 ml). CCK-8 (0.5 μg/kg ip) reduced 10-min emptying to 1.36 ± 0.3 ml. Pretreatment with MK-801 did not significantly attenuate CCK-8-induced reduction of gastric emptying (0.9 ± 0.4 ml). This series of experiments demonstrates that blockade of NMDA ion channels reverses inhibition of real feeding by CCK. However, neither inhibition of sham feeding nor inhibition of gastric emptying by CCK is attenuated by MK-801. Therefore, increased food intake after NMDA receptor blockade is not caused by a direct interference with CCK-induced satiation. Rather, increased real feeding, either in the presence or absence of CCK, depends on blockade of NMDA receptor participation in other postoral feedback signals such as gastric sensation or gastric tone.

scholarly journals Role of Endogenous Interleukin-18 in Resolving Wild-Type and Attenuated Salmonella typhimuriumInfections

1999 ◽  
Vol 67 (12) ◽  
pp. 6242-6248 ◽  
Author(s):  
Jody K. Dybing ◽  
Nancy Walters ◽  
David W. Pascual
Keyword(s):  
Survival Rate ◽  
Oral Challenge ◽  
Interleukin 12 ◽  
Intracellular Pathogens ◽  
Wild Type ◽  
Interleukin 18 ◽  
Ifn Γ ◽  
Negative Mutant ◽  
Stimulation Of

ABSTRACT The stimulation of gamma interferon (IFN-γ) has been shown to be essential in resolving infections by intracellular pathogens. As such, several different cytokines including, interleukin-12 (IL-12) and IL-18, can induce IFN-γ. To resolve Salmonellainfections, the stimulation of IL-12 and IFN-γ are important for mediating its clearance. In this present study, the relevance of IL-18 in protection against oral challenge with Salmonella typhimurium was investigated to determine the role of this IFN-γ-promoting cytokine. Rabbit anti-murine IL-18 antisera was generated and administered prior to the oral challenge of BALB/c and IL-12p40-deficient knockout (IL-12KO) mice with a wild-type S. typhimurium strain. The median survival time was reduced by 2 days for the anti-IL-18-treated BALB/c mice, while no significant reduction in survival rate for the anti-IL-18-treated IL-12KO mice was observed compared to vehicle-treated mice. To investigate the contribution of IL-18 to resolving Salmonella infections, an attenuated aro-negative mutant (H647) was orally administered to BALB/c mice. This Salmonella infection induced both IL-12 and IFN-γ in both the Peyer's patches and the spleens. In vehicle-treated mice, Peyer's patch IL-12 peaked by 24 h, while IL-18 levels peaked at 3 days, suggesting sequential support by these cytokines for IFN-γ. Anti-IL-18 treatment exerted its greatest effect upon the mucosal compartment, limiting early IFN-γ production. However, anti-IL-18 treatment had little effect upon splenic IFN-γ levels until late in the response. Infection of IL-12KO mice with H647 strain induced IFN-γ, but it was not supported by IL-18, although IL-18 levels were reduced by this treatment. These results suggest that IL-18 does contribute to the clearance of S. typhimurium and that endogenously induced IL-18 could not substitute for IL-12.

scholarly journals Inactivation of Ppp1r15a minimises weight gain and insulin resistance during caloric excess in mice

2018 ◽  
Author(s):  
Vruti Patel ◽  
Guillaume Bidault ◽  
Joseph E. Chambers ◽  
Stefania Carobbio ◽  
Angharad J. T. Everden ◽  
...  
Keyword(s):  
Weight Gain ◽  
Food Intake ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Standard Diet ◽  
Wild Type ◽  
Diet Induced Obesity ◽  
Caloric Excess ◽  
Deficient Mice

AbstractPhosphorylation of the translation initiation factor eIF2α within the mediobasal hypothalamus is known to suppress food intake, but the role of the eIF2α phosphatases in regulating body weight is poorly understood. Mice deficient in active PPP1R15A, a stress-inducible eIF2α phosphatase, are healthy and more resistant to endoplasmic reticulum stress than wild type controls. We report that when Ppp1r15a mutant mice are fed a high fat diet they gain less weight than wild type littermates owing to reduced food intake. This results in healthy leaner Ppp1r15a mutant animals with reduced hepatic steatosis and improved insulin sensitivity, albeit with a modest defect in insulin secretion. By contrast, no weight differences are observed between wild type and Ppp1r15a deficient mice fed a standard diet. We conclude that mice lacking the C-terminal PP1-binding domain of PPP1R15A show reduced dietary intake and preserved glucose tolerance. Our data indicate that this results in reduced weight gain and protection from diet-induced obesity.

Sign in / Sign up

Export Citation Format

Share Document