scholarly journals Upregulation of bile acid receptor TGR5 and nNOS in gastric myenteric plexus is responsible for delayed gastric emptying after chronic high-fat feeding in rats

2015 ◽  
Vol 308 (10) ◽  
pp. G863-G873 ◽  
Author(s):  
Hui Zhou ◽  
Shiyi Zhou ◽  
Jun Gao ◽  
Guanpo Zhang ◽  
Yuanxu Lu ◽  
...  
Keyword(s):  
Bile Acid ◽  
Gastric Emptying ◽  
Myenteric Plexus ◽  
High Fat Diet ◽  
Delayed Gastric Emptying ◽  
High Fat ◽  
Bile Acid Receptor ◽  
Fat Feeding ◽  
Nanc Relaxation ◽  
Nnos Expression

Chronic high-fat feeding is associated with functional dyspepsia and delayed gastric emptying. We hypothesize that high-fat feeding upregulates gastric neuronal nitric oxide synthase (nNOS) expression, resulting in delayed gastric emptying. We propose this is mediated by increased bile acid action on bile acid receptor 1 (TGR5) located on nNOS gastric neurons. To test this hypothesis, rats were fed regular chow or a high-fat diet for 2 wk. Rats fed the high-fat diet were subjected to concurrent feeding with oral cholestyramine or terminal ileum resection. TGR5 and nNOS expression in gastric tissue was measured by immunohistochemistry, PCR, and Western blot. Gastric motility was assessed by organ bath and solid-phase gastric emptying studies. The 2-wk high-fat diet caused a significant increase in neurons coexpressing nNOS and TGR5 in the gastric myenteric plexus and an increase in nNOS and TGR5 gene expression, 67 and 111%, respectively. Enhanced nonadrenergic, noncholinergic (NANC) relaxation, deoxycholic acid (DCA)-induced inhibition in fundic tissue, and a 26% delay in gastric emptying accompanied these changes. A 24-h incubation of whole-mount gastric fundus with DCA resulted in increased nNOS and TGR5 protein expression, 41 and 37%, respectively. Oral cholestyramine and terminal ileum resection restored the enhanced gastric relaxation, as well as the elevated nNOS and TGR5 expression evoked by high-fat feeding. Cholestyramine also prevented the delay in gastric emptying. We conclude that increased levels of circulatory bile acids induced by high-fat feeding upregulate nNOS and TGR5 expression in the gastric myenteric plexus, resulting in enhanced NANC relaxation and delayed gastric emptying.

scholarly journals Mechanistic role of antioxidants in rescuing delayed gastric emptying in high fat diet induced diabetic female mice

2021 ◽  
Vol 137 ◽  
pp. 111370
Author(s):  
Chethan Sampath ◽  
Derek Wilus ◽  
Mohammad Tabatabai ◽  
Michael L. Freeman ◽  
Pandu R. Gangula
Keyword(s):  
Gastric Emptying ◽  
High Fat Diet ◽  
Delayed Gastric Emptying ◽  
High Fat ◽  
Female Mice

Yeast β-glucan reduces obesity-associated Bilophila abundance and modulates bile acid metabolism in healthy and high-fat diet mouse models

2021 ◽  
Author(s):  
Sik Yu So ◽  
Qinglong Wu ◽  
Kin Sum Leung ◽  
Zuzanna Maria Kundi ◽  
Tor C Savidge ◽  
...  
Keyword(s):  
Bile Acid ◽  
Gut Microbiota ◽  
High Fat Diet ◽  
Metabolic Health ◽  
Metabolic Phenotype ◽  
Bile Acid Metabolism ◽  
Microbiota Composition ◽  
High Fat ◽  
Mrna Accumulation ◽  
Gut Microbiota Composition

Emerging evidence links dietary fiber with altered gut microbiota composition and bile acid signaling in maintaining metabolic health. Yeast β-glucan (Y-BG) is a dietary supplement known for its immunomodulatory effect, yet its impact on the gut microbiota and bile acid composition remains unclear. This study investigated whether dietary forms of Y-BG modulate these gut-derived signals. We performed 4-week dietary supplementation in healthy mice to evaluate effects of different fiber composition (soluble vs particulate Y-BG) and dose (0.1 vs. 2%). We found that 2% particulate Y-BG induced robust gut microbiota community shifts with elevated liver Cyp7a1 mRNA abundance and bile acid synthesis. These diet-induced responses were notably different when compared to the prebiotic inulin, and included a marked reduction in fecal Bilophila abundance which we demonstrated as translatable to obesity in population-scale American Gut and TwinsUK clinical cohorts. This prompted us to test whether 2% Y-BG maintained metabolic health in mice fed 60% HFD over 13 weeks. Y-BG consistently altered the gut microbiota composition and reduced Bilophila abundance, with trends observed in improvement of metabolic phenotype. Notably, Y-BG improved insulin sensitization and this was associated with enhanced ileal Glpr1r mRNA accumulation and reduced Bilophila abundance. Collectively, our results demonstrate that Y-BG modulates gut microbiota community composition and bile acid signaling, but the dietary regime needs to be optimized to facilitate clinical improvement in metabolic phenotype in an aggressive high-fat diet animal model.

Liver disease with altered bile acid transport in Niemann-Pick C mice on a high-fat, 1% cholesterol diet

2005 ◽  
Vol 289 (2) ◽  
pp. G300-G307 ◽  
Author(s):  
Robert P. Erickson ◽  
Achyut Bhattacharyya ◽  
Robert J. Hunter ◽  
Randall A. Heidenreich ◽  
Nathan J. Cherrington
Keyword(s):  
Liver Disease ◽  
Bile Acid ◽  
High Fat Diet ◽  
Density Lipoprotein ◽  
Cholestatic Hepatitis ◽  
Diffuse Fibrosis ◽  
Acid Transport ◽  
High Fat ◽  
Bile Acid Transport ◽  
Niemann Pick

Cholestatic hepatitis is frequently found in Niemann-Pick C (NPC) disease. We studied the influence of diet and the low density lipoprotein receptor (LDLR, Ldlr in mice, known to be the source of most of the stored cholesterol) on liver disease in the mouse model of NPC. Npc1−/− mice of both sexes, with or without the Ldlr knockout, were fed a 18% fat, 1% cholesterol (“high-fat”) diet and were evaluated by chemical and histological methods. Bile acid transporters [multidrug resistance protein (Mrps) 1–5; Ntcp, Bsep, and OatP1, 2, and 4] were quantitated by real-time RT-PCR. Many mice died prematurely (within 6 wk) with hepatomegaly. Histopathology showed an increase in macrophage and hepatocyte lipids independent of Ldlr genotype. Non-zone-dependent diffuse fibrosis was found in the surviving mice. Serum alanine aminotransferase was elevated in Npc1−/− mice on the regular diet and frequently became markedly elevated with the high-fat diet. Serum cholesterol was increased in the controls but not the Npc1−/− mice on the high-fat diet; it was massively increased in the Ldlr−/− mice. Esterified cholesterol was greatly increased by the high-fat diet, independent of Ldlr genotype. γ-Glutamyltransferase was also elevated in Npc1−/− mice, more so on the high-fat diet. Mrps 1–5 were elevated in Npc1−/− liver and became more elevated with the high-fat diet; Ntcp, Bsep, and OatP2 were elevated in Npc1−/− liver and were suppressed by the high-fat diet. In conclusion, Npc1−/− mice on a high-fat diet provide an animal model of NPC cholestatic hepatitis and indicate a role for altered bile acid transport in its pathogenesis.

Adaptation to high-fat diet accelerates emptying of fat but not carbohydrate test meals in humans

2002 ◽  
Vol 282 (2) ◽  
pp. R366-R371 ◽  
Author(s):  
K. E. Castiglione ◽  
N. W. Read ◽  
S. J. French
Keyword(s):  
Gastric Emptying ◽  
Dietary Intake ◽  
Test Meal ◽  
High Fat Diet ◽  
Lag Phase ◽  
High Fat ◽  
Free Living ◽  
Gastric Emptying Rate ◽  
High Carbohydrate ◽  
Before And After

Previous work has shown that the gastric emptying rate in animals and humans can adapt due to previous dietary intake. The present study investigated whether adaptation in gastric emptying rate due to consumption of a high-fat diet (HFD) is nutrient specific in humans. Gastric emptying of high-fat and high-carbohydrate test meals was measured (using gamma scintigraphy) before and after consumption of an HFD for 14 days in eight free-living male volunteers. Visual analog ratings of appetite were recorded throughout each test. There was no effect of HFD on any parameters of gastric emptying rate (lag phase, half-emptying time, and linear emptying rate) measured for carbohydrate test meals. HFD led to an acceleration of the linear emptying rate of the high-fat test meal (0.36 vs. 0.47%/min; P < 0.05). All meals reduced appetite ratings, but there were no differences between tests. These results support our previous findings of accelerated gastric emptying of high-fat test meals following an HFD and show that these changes appear to be nutrient specific, confirming recent studies in rats.

scholarly journals Estradiol treatment or modest exercise improves hepatic health and mitochondrial outcomes in female mice following ovariectomy

2021 ◽  
Author(s):  
Kelly N. Z. Fuller ◽  
Colin S. McCoin ◽  
Alex T. Von Schulze ◽  
Claire J. Houchen ◽  
Michael A. Choi ◽  
...  
Keyword(s):  
Bile Acid ◽  
Mitochondrial Function ◽  
High Fat Diet ◽  
Acid Metabolism ◽  
Bile Acid Metabolism ◽  
High Fat ◽  
Estradiol Treatment ◽  
Respiratory Capacity ◽  
Female Mice ◽  
Mitochondrial Respiratory

We recently reported that compared to males, female mice have increased hepatic mitochondrial respiratory capacity and are protected against high-fat diet-induced steatosis. Here we sought to determine the role of estrogen in hepatic mitochondrial function, steatosis, and bile acid metabolism in female mice, as well as investigate potential benefits of exercise in the absence or presence of estrogen via ovariectomy (OVX). Female C57BL mice (n=6 per group) were randomly assigned to sham surgery (Sham), ovariectomy (OVX), or OVX plus estradiol replacement therapy (OVX+Est). Half of the mice in each treatment group were sedentary (SED) or had access to voluntary wheel running (VWR). All mice were fed a high-fat diet (HFD) and were housed at thermoneutral temperatures. We assessed isolated hepatic mitochondrial respiratory capacity using the Oroboros O2k with both pyruvate and palmitoylcarnitine as substrates. As expected, OVX mice presented with greater hepatic steatosis, weight gain, and fat mass gain compared to Sham and OVX+Est animals. Hepatic mitochondrial coupling (Basal/State 3 respiration) with pyruvate was impaired following OVX, but both VWR and estradiol treatment rescued coupling to levels greater than or equal to Sham animals. Estradiol and exercise also had different effects on liver electron transport chain protein expression depending on OVX status. Markers of bile acid metabolism and excretion were also impaired by ovariectomy but rescued with estradiol add-back. Together our data suggest that estrogen depletion impairs hepatic mitochondrial function and liver health, and that estradiol replacement and modest exercise can aid in rescuing this phenotype.

scholarly journals Hypocholesterolaemic effect of whole-grain highland hull-less barley in rats fed a high-fat diet

2018 ◽  
Vol 119 (10) ◽  
pp. 1102-1110 ◽  
Author(s):  
Xuejuan Xia ◽  
Guannan Li ◽  
Jiaxin Song ◽  
Jiong Zheng ◽  
Jianquan Kan
Keyword(s):  
Bile Acid ◽  
High Fat Diet ◽  
Control Diet ◽  
Ldl Receptor ◽  
Acid Synthesis ◽  
Farnesoid X Receptor ◽  
High Dose ◽  
Whole Grain ◽  
Sprague Dawley ◽  
High Fat

AbstractWhole-grain highland hull-less barley (WHLB) contains high amounts of bioactive compounds that potentially exhibit cholesterol-lowering effects. This study investigated the hypocholesterolaemic effect of WHLB. A total of seventy-two male Sprague–Dawley rats were divided into four groups and were fed with the normal control diet, high-fat diet (HFD) and HFD containing low or high dose (10 or 48·95 %) of WHLB. High dose of WHLB significantly decreased the organ indexes of liver and abdominal fat and lipid levels of plasma and liver in HFD rats. The lipid regulation effect of WHLB, which was reconfirmed through hepatocyte morphologic observation, was accompanied by a large excretion of bile acids in the small intestinal contents and the faeces. Real-time PCR analyses, which were further reconfirmed through Western blot analyses, revealed that a high dose of WHLB significantly enhanced the hepatic expressions of AMP-activated protein kinase α, cholesterol 7α-hydroxylase, LDL receptor, liver X receptor, and PPARα and decreased the expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase. It also enhanced the ileal expression of farnesoid X receptor and resulted in the decrease of expression of apical sodium-dependent bile acid transporter. WHLB exhibited hypocholesterolaemic effects mainly by inhibiting cholesterol synthesis, cholesterol accumulation in peripheral tissue, and bile acid reabsorption and by stimulating bile acid synthesis.

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