The gastrointestinal peptides and nutrition

1983 ◽  
Vol 61 (4) ◽  
pp. 282-289 ◽  
Author(s):  
J. C. Brown ◽  
C. H. S. McIntosh ◽  
R. A. Pederson

Gastrointestinal (GI) peptides have been identified in endocrine cells and nerve fibres throughout the GI tract. They play both a direct and indirect role in the regulation of food intake, digestion, and absorption. The rate at which food is absorbed is dependent upon the rates of gastric emptying, intestinal transit, membrane transport, and enzymatic degradation. The control of pepsin secretion is intimately linked to that of acid secretion and stimulatory peptides, e.g., gastrin and bombesin. Inhibitors of acid secretion such as gastric inhibitory polypeptide (GIP), vasoactive intestinal peptide (VIP), secretin, and glucagon also control pepsin secretion. Powerful inhibitory reflexes, both nervous and hormonal, operate from the duodenum to slow gastric emptying and the most compelling evidence exists for the involvement of neurally released VIP. However, a unifying concept for the role of peptides in the control of intestinal motility is lacking. It is well established that the enzyme component of pancreatic secretion is controlled by the peptide cholecystokinin (CCK) and the aqueous component by secretin. Nutrient absorption can be affected by the endocrine pancreas and by somatostatin. Control of luminal enzyme secretion is increased by CCK, secretin, GIP, VIP, glucagon, and gastrin. Peptides influence the rate and direction of electrolyte and attendant water movement. The secretory actions of VIP are well documented. Peptides, again notably VIP, probably influence digestion and absorption via blood flow changes. Evidence has accumulated that gut hormones stimulate insulin release from the pancreas. The peptide, GIP, has been demonstrated to be a hormone involved in this mechanism and has been hypothesized to be a causal agent in disease states involving hyperinsulinemta, e.g., obesity and maturity onset diabetes. The hypothalamus is recognized to be the major regulatory area for appetite. It receives rich peptidergic innervation as well as being influenced by exogenous peptides. CCK has been shown to inhibit food intake. The presence of this peptide in the brain as well as the gut has led to the suggestion that it is a satiety hormone. However, problems with experimental design render equivocal the role of CCK and other peptides in the control of food intake.

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1158
Author(s):  
Lizeth Cifuentes ◽  
Michael Camilleri ◽  
Andres Acosta

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.


2006 ◽  
Vol 291 (4) ◽  
pp. G611-G620 ◽  
Author(s):  
Lixin Wang ◽  
Nicole R. Basa ◽  
Almaas Shaikh ◽  
Andrew Luckey ◽  
David Heber ◽  
...  

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.


1989 ◽  
Vol 256 (1) ◽  
pp. R181-R186
Author(s):  
A. Bado ◽  
M. J. Lewin ◽  
M. Dubrasquet

The brain and gut peptide bombesin has been reported both to stimulate gastric secretion and to induce satiety. To understand how the peripheral administration of bombesin affects food intake and whether gastric mechanisms are involved, a comparative study of the doses of bombesin active on gastric secretion, gastric emptying, and food intake was undertaken in cats provided with a gastric fistula and a denervated Heidenhain pouch. The smallest dose of intravenous bombesin that stimulated significantly basal acid secretion (20 pmol.kg-1.h-1) by the gastric fistula also enhanced meal-stimulated acid secretion by the Heidenhain pouch (+138%, P less than 0.01), delayed gastric emptying of a liquid protein meal (-30%, P less than 0.01), and suppressed food intake when the test meal was allowed to reach the stomach (-15%, P less than 0.01). Conversely, in sham-feeding experiments, the same dose of bombesin increased food intake (+35%, P less than 0.01). In full-day experiments conducted in nonfasted cats, bombesin decreased both the food intake in the 4-h period after the infusion and the daily food intake, whereas octapeptide cholecystokinin induced a transient satiety but did not decrease daily food intake. These results indicate that in cats the interaction of bombesin with "pregastric" mechanisms is not sufficient to induce satiety and that a relation could exist between the effects of bombesin on gastric secretion, emptying, and food intake. A single class of receptors might be involved in these peripheral effects of bombesin.


1965 ◽  
Vol 209 (2) ◽  
pp. 319-323 ◽  
Author(s):  
Peter T. Ridley ◽  
Frank P. Brooks

Fasting gastric secretion and secretion during insulin hypoglycemia were collected from hypothalamic hyperphagic rats equipped with chronic gastric fistula in an attempt to correlate the hypothalamic neural mechanisms controlling food intake with gastric secretion. The interdigestive or basal fasting secretion of rats rendered hyperphagic by stereotaxic ablation of the ventromedial nuclei was significantly increased in volume, acid concentration and output, and pepsin output when compared with control and sham-operated rats and rats with hypothalamic lesions without hyperphagia. Hypothalamic hyperphagic rats did not show a significant increase in gastric secretion during insulin hypoglycemia, whereas the other groups did. The levels of hypoglycemia induced by insulin were comparable in all groups. These studies suggest an important role of the ventromedial nuclei in the central regulation of acid and pepsin secretion, and also relate the hypothalamic neural control of gastric secretion to that of food intake. The results also indicate that this nucleus is involved either as a "center" or pathway in the augmentation of gastric secretion by insulin hypoglycemia.


2009 ◽  
Vol 68 (1) ◽  
pp. 89-97 ◽  
Author(s):  
Miriam Clegg ◽  
Amir Shafat

Dietary fat is an important factor in the aetiology of obesity and the metabolic syndrome. It has been widely debated whether gastric emptying (GE) is altered in obesity. GE times have been reported as both longer and shorter in obese individuals compared with matched lean individuals. However, the general consensus is that GE is accelerated and satiety is lower in obesity. Research has implicated a high-fat (HF) diet in these findings. A single HF meal has a longer GE time than a low-fat meal and can even delay GE of the subsequent meal. However, an HF diet has shown different effects. Feeding a HF diet adapts gastrointestinal function to reduce GE times in comparison with a low-fat diet. Increased GE may lead to decreased satiety and faster onset of subsequent eating episodes. Further results have suggested that consuming an HF diet for 14 d increases the GE rate of HF food but not low-fat food. Consuming HF diets for 2 weeks has also been shown to increase food intake. Decreased satiation following an HF diet may cause increased food intake and a positive energy balance, potentially resulting in a gradual increase in adiposity. Recent results have suggested that gastrointestinal transit is accelerated following only 3 d on a HF diet. The variable GE times reported in obesity may be associated with interactions between the HF diet and obesity and not simply the obese state.


Gut ◽  
2020 ◽  
Vol 69 (9) ◽  
pp. 1620-1628 ◽  
Author(s):  
Sei Higuchi ◽  
Tiara R Ahmad ◽  
Donovan A Argueta ◽  
Pedro A Perez ◽  
Chen Zhao ◽  
...  

ObjectivesLipid mediators in the GI tract regulate satiation and satiety. Bile acids (BAs) regulate the absorption and metabolism of dietary lipid in the intestine, but their effects on lipid-regulated satiation and satiety are completely unknown. Investigating this is challenging because introducing excessive BAs or eliminating BAs strongly impacts GI functions. We used a mouse model (Cyp8b1–/– mice) with normal total BA levels, but alterations in the composition of the BA pool that impact multiple aspects of intestinal lipid metabolism. We tested two hypotheses: BAs affect food intake by (1) regulating production of the bioactive lipid oleoylethanolamide (OEA), which enhances satiety; or (2) regulating the quantity and localisation of hydrolysed fat in small intestine, which controls gastric emptying and satiation.DesignWe evaluated OEA levels, gastric emptying and food intake in wild-type and Cyp8b1–/– mice. We assessed the role of the fat receptor GPR119 in these effects using Gpr119–/– mice.ResultsCyp8b1–/– mice on a chow diet showed mild hypophagia. Jejunal OEA production was blunted in Cyp8b1–/– mice, thus these data do not support a role for this pathway in the hypophagia of Cyp8b1–/– mice. On the other hand, Cyp8b1 deficiency decreased gastric emptying, and this was dependent on dietary fat. GPR119 deficiency normalised the gastric emptying, gut hormone levels, food intake and body weight of Cyp8b1–/– mice.ConclusionBAs regulate gastric emptying and satiation by determining fat-dependent GPR119 activity in distal intestine.


Endocrinology ◽  
2009 ◽  
Vol 150 (11) ◽  
pp. 4911-4919 ◽  
Author(s):  
Andreas Stengel ◽  
Miriam Goebel ◽  
Lixin Wang ◽  
Jean Rivier ◽  
Peter Kobelt ◽  
...  

Nesfatin-1, derived from nucleobindin2, is expressed in the hypothalamus and reported in one study to reduce food intake (FI) in rats. To characterize the central anorexigenic action of nesfatin-1 and whether gastric emptying (GE) is altered, we injected nesfatin-1 into the lateral brain ventricle (intracerebroventricular, icv) or fourth ventricle (4v) in chronically cannulated rats or into the cisterna magna (intracisternal, ic) under short anesthesia and compared with ip injection. Nesfatin-1 (0.05 μg/rat, icv) decreased 2–3 h and 3–6 h dark-phase FI by 87 and 45%, respectively, whereas ip administration (2 μg/rat) had no effect. The corticotropin-releasing factor (CRF)1/CRF2 antagonist astressin-B or the CRF2 antagonist astressin2-B abolished icv nesfatin-1’s anorexigenic action, whereas an astressin2-B analog, devoid of CRF-receptor binding affinity, did not. Nesfatin-1 icv induced a dose-dependent reduction of GE by 26 and 43% that was not modified by icv astressin2-B. Nesfatin-1 into the 4v (0.05 μg/rat) or ic (0.5 μg/rat) decreased cumulative dark-phase FI by 29 and 60% at 1 h and by 41 and 37% between 3 and 5 h, respectively. This effect was neither altered by ic astressin2-B nor associated with changes in GE. Cholecystokinin (ip) induced Fos expression in 43% of nesfatin-1 neurons in the paraventricular hypothalamic nucleus and 24% of those in the nucleus tractus solitarius. These data indicate that nesfatin-1 acts centrally to reduce dark phase FI through CRF2-receptor-dependent pathways after forebrain injection and CRF2-receptor-independent pathways after hindbrain injection. Activation of nesfatin-1 neurons by cholecystokinin at sites regulating food intake may suggest a role in gut peptide satiation effect.


Endocrinology ◽  
2011 ◽  
Vol 152 (3) ◽  
pp. 979-988 ◽  
Author(s):  
Lu Xu ◽  
Wim J. J. M. Scheenen ◽  
Rebecca L. Leshan ◽  
Christa M. Patterson ◽  
Carol F. Elias ◽  
...  

A recent study systematically characterized the distribution of the long form of the leptin receptor (LepRb) in the mouse brain and showed substantial LepRb mRNA expression in the nonpreganglionic Edinger-Westphal nucleus (npEW) in the rostroventral part of the midbrain. This nucleus hosts the majority of urocortin 1 (Ucn1) neurons in the rodent brain, and because Ucn1 is a potent satiety hormone and electrical lesioning of the npEW strongly decreases food intake, we have hypothesized a role of npEW-Ucn1 neurons in leptin-controlled food intake. Here, we show by immunohistochemistry that npEW-Ucn1 neurons in the mouse contain LepRb and respond to leptin administration with induction of the Janus kinase 2-signal transducer and activator of transcription 3 pathway, both in vivo and in vitro. Furthermore, systemic leptin administration increases the Ucn1 content of the npEW significantly, whereas in mice that lack LepRb (db/db mice), the npEW contains considerably reduced amount of Ucn1. Finally, we reveal by patch clamping of midbrain Ucn1 neurons that leptin administration reduces the electrical firing activity of the Ucn1 neurons. In conclusion, we provide ample evidence for leptin actions that go beyond leptin's well-known targets in the hypothalamus and propose that leptin can directly influence the activity of the midbrain Ucn1 neurons.


Endocrinology ◽  
2008 ◽  
Vol 150 (1) ◽  
pp. 153-160 ◽  
Author(s):  
Andreas Stengel ◽  
Miriam Goebel ◽  
Mulugeta Million ◽  
Mary P. Stenzel-Poore ◽  
Peter Kobelt ◽  
...  

Corticotropin-releasing factor (CRF) overexpressing (OE) mice are a genetic model that exhibits features of chronic stress. We investigated whether the adaptive feeding response to a hypocaloric challenge induced by food deprivation is impaired under conditions of chronic CRF overproduction. Food intake response to a 16-h overnight fast and ip injection of gut hormones regulating food intake were compared in CRF-OE and wild type (WT) littermate mice along with brain Fos expression, circulating ghrelin levels, and gastric emptying of a nonnutrient meal. CRF-OE mice injected ip with saline showed a 47 and 44% reduction of 30-min and 4-h cumulative food intake response to an overnight fast, respectively, compared with WT. However, the 30-min food intake decrease induced by ip cholecystokinin (3 μg/kg) and increase by ghrelin (300 μg/kg) were similar in CRF-OE and WT mice. Overnight fasting increased the plasma total ghrelin to similar levels in CRF-OE and WT mice, although CRF-OE mice had a 2-fold reduction of nonfasting ghrelin levels. The number of Fos-immunoreactive cells induced by fasting in the arcuate nucleus was reduced by 5.9-fold in CRF-OE compared with WT mice whereas no significant changes were observed in other hypothalamic nuclei. In contrast, fasted CRF-OE mice displayed a 5.6-fold increase in Fos-immunoreactive cell number in the dorsal motor nucleus of the vagus nerve and a 34% increase in 20-min gastric emptying. These findings indicate that sustained overproduction of hypothalamic CRF in mice interferes with fasting-induced activation of arcuate nucleus neurons and the related hyperphagic response. Sustained over-production of brain corticotrophin-releasing factor interferes with fasting-activated neuronal activation in the arcuate nucleus and results in reduction of food intake dissociated from gastric emptying.


2012 ◽  
Vol 59 (3) ◽  
pp. 197-206 ◽  
Author(s):  
Anna Del Prete ◽  
Maddalena Iadevaia ◽  
Carmelina Loguercio

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