American journal of physiology. Gastrointestinal and liver physiology最新文献

{"title":"Cinnabarinic acid protects against metabolic dysfunction-associated steatohepatitis by activating aryl hydrocarbon receptor-dependent AMPK signaling.","authors":"Nikhil Y Patil, Iulia Rus, Felix Ampadu, Hassan M Abu Shukair, Sarah Bonvicino, Richard S Brush, Elena Eaton, Martin-Paul Agbaga, Tae Gyu Oh, Jacob E Friedman, Aditya D Joshi","doi":"10.1152/ajpgi.00337.2024","DOIUrl":"10.1152/ajpgi.00337.2024","url":null,"abstract":"<p><p>Metabolic dysfunction-associated steatohepatitis (MASH) is an advanced form of metabolic dysfunction-associated steatotic liver disease (MASLD) characterized by the accumulation of fats in the liver, chronic inflammation, hepatocytic ballooning, and fibrosis. This study investigates the significance of hepatic aryl hydrocarbon receptor (AhR) signaling in cinnabarinic acid (CA)-mediated protection against MASH. Here, we report that livers of high-fat, high-fructose, high-cholesterol diet-fed hepatocyte-specific aryl hydrocarbon receptor knockout mice (AhR-hKO) exhibited aggravated steatosis, inflammation, and fibrosis compared with control AhR-floxed livers. Moreover, treatment with a tryptophan catabolite, CA, reduced body weight gain and significantly attenuated hepatic steatosis, inflammation, ballooning, fibrosis, and liver injury only in AhR-floxed but not in AhR-hKO mice, strongly indicating that the CA-mediated protection against steatohepatitis is AhR-dependent. Furthermore, protection against lipotoxicity by CA-activated AhR signaling was confirmed by utilizing an in vitro human hepatocyte model of MASLD. Mechanistically, CA-induced AhR-dependent signaling augmented AMP-activated protein kinase (AMPK), leading to the upregulation of peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC1α) and attenuation of sterol regulatory element-binding protein-1 (SREBP1) to regulate hepatic lipid metabolism. Collectively, our findings indicate that CA-mediated protection against MASH is dependent on hepatic AhR signaling, and selective endogenous AhR agonists that regulate lipogenesis can serve as promising future therapeutics against MASLD.<b>NEW & NOTEWORTHY</b> The study showed that the absence of AhR in hepatocytes results in exacerbated metabolic dysfunction-associated steatohepatitis (MASH) in mice subjected to a Western-style high-fat, high-fructose, high-cholesterol diet. Moreover, treatment with a tryptophan catabolite, cinnabarinic acid (CA), mitigated hallmarks of MASH in an AhR-dependent manner. In conclusion, the study delineates the significance of hepatic AhR-dependent AMPK signaling in CA-mediated protection against MASH.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G433-G447"},"PeriodicalIF":3.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143584376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Progressive impairment in gastric and duodenal slow waves and autonomic function during progression of type 2 diabetes in rats.","authors":"Gaojue Wu, Fei Li, Yan Li, Shiying Li, Md Jahangir Alam, Jiande D Z Chen","doi":"10.1152/ajpgi.00278.2024","DOIUrl":"10.1152/ajpgi.00278.2024","url":null,"abstract":"<p><p>The abnormalities of gastrointestinal (GI) slow waves play key roles in the pathophysiology of diabetic gastroparesis, which is highly prevalent in type 2 diabetes (T2D). Although relatively well-investigated in diabetic enteric neuropathy, abnormalities and progressive impairments of gastric slow waves (GSWs) and duodenal slow waves (DSWs) are underinvestigated during the progression of T2D. The aim of this study was to explore alterations in GSW and DSW during the development of diabetes induced by high-fat diet (HFD) followed by a low dose of streptozotocin (STZ). Weekly recordings of slow waves from healthy, prediabetic to diabetes stages exhibited a progressively decreased percentage of normal slow waves (%NSW) starting after HFD feeding (prediabetic stage) in the fasting state and starting after STZ injection (diabetic stage) in the postprandial state. The postprandial increase in the power of slow waves observed in normal control rats was absent starting from 2 wk after HFD and persisted after STZ. The mechanism might be attributed to both progressively increased blood glucose (BG) and impaired autonomic function in view of the following results: <i>1</i>) the %NSW was negatively correlated with the fasting BG; <i>2</i>) during the oral glucose tolerance test, %NSW of DSW and BG exhibited a positive correlation in rats with hemoglobin A1C (HbA1C) < 5.0%, but a negative correlation in rats with HbA1C ≥ 5.0%; and <i>3</i>) in comparison with baseline (healthy stage) of the same cohort, plasma pancreatic polypeptide (reflecting vagal activity) was progressively decreased, whereas plasma norepinephrine (reflecting sympathetic activity) was progressively increased.<b>NEW & NOTEWORTHY</b> This study recorded the progressive impairment in the regularity of gastric and duodenal slow waves in a rat model mimicking the progression to type 2 diabetes including the stage of health, prediabetic stage, and diabetes. The progressive impairment in gastric/duodenal slow waves might be attributed to the progressive increase in blood glucose and impairment in autonomic function.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G386-G398"},"PeriodicalIF":3.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143490388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Duodenogastric reflux in health and disease: insights from a computational fluid dynamics model of the stomach.","authors":"Sharun Kuhar, Jung-Hee Seo, Pankaj Jay Pasricha, Michael Camilleri, Rajat Mittal","doi":"10.1152/ajpgi.00241.2024","DOIUrl":"10.1152/ajpgi.00241.2024","url":null,"abstract":"<p><p>The stomach is responsible for physically and chemically processing the ingested meal before controlled emptying into the duodenum through the pyloric sphincter. An incompetent pylorus allows reflux from the duodenum back into the stomach, and if the amount of reflux is large enough, it could alter the low-pH environment of the stomach and erode the mucosal lining of the lumen. In some cases, the regurgitated contents can also reach the esophagus, leading to additional complications. In this work, \"StomachSim\", an in silico model of the fluid dynamics of the stomach, is used to study the mechanism of duodenogastric reflux. The effects of variations in food properties and motility disorders on reflux are investigated. The simulations show that the primary driver of reflux is the relaxation of the antrum after a stomach contraction terminates near the pylorus. The region of the stomach walls exposed to the regurgitated contents depends significantly on the density of the stomach contents. For stomach contents of higher viscosity, the increased pressure required to maintain gastric emptying reduces the amount of duodenogastric reflux. Concomitant stomach motility disorders that weaken the relaxation of the walls also affect the amount of reflux. The study illustrates the utility of in silico models in analyzing the factors at play in gastrointestinal diseases.<b>NEW & NOTEWORTHY</b> An in silico model of the stomach is presented to study the phenomenon of duodenogastric reflux. We use the model to investigate the role of pyloric incompetence, food properties, and gastroparesis on reflux. This first-ever in silico study of duodenogastric reflux provides new insights into the mechanisms and factors implicated in this reflux and the sequelae of conditions that result from the exposure of the stomach lumen to bile.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G411-G425"},"PeriodicalIF":3.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143051372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of circulatory monocytes trafficking and transitioning to gastric resident macrophages in diabetic gastroparesis.","authors":"Rajan Singh","doi":"10.1152/ajpgi.00053.2025","DOIUrl":"10.1152/ajpgi.00053.2025","url":null,"abstract":"","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G429-G432"},"PeriodicalIF":3.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combination of dietary fiber and exercise training improves fat loss in mice but does not ameliorate MASLD more than exercise alone.","authors":"Artemiy Kovynev, Mikołaj M Charchuta, Amina Begtašević, Quinten R Ducarmon, Patrick C N Rensen, Milena Schönke","doi":"10.1152/ajpgi.00317.2024","DOIUrl":"10.1152/ajpgi.00317.2024","url":null,"abstract":"<p><p>Lifestyle interventions, such as diet and exercise, are currently the main therapies against metabolic dysfunction-associated steatotic liver disease (MASLD). However, not much is known about the combined impact of fiber and exercise on the modulation of gut-liver axis and MASLD amelioration. Here, we studied the impact of the combination of exercise training and a fiber-rich diet on the amelioration of MASLD. Male APOE*3-Leiden.CETP mice were fed a high-fat high-cholesterol diet with or without the addition of fiber (10% inulin) and exercise trained on a treadmill, or remained sedentary. Exercise training and fiber supplementation reduced fat mass gain and lowered plasma glucose levels. Only the combination treatment, however, induced fat loss and decreased plasma triglyceride and cholesterol levels compared with sedentary control mice. Exercise training with and without the addition of fiber had a similar ameliorating effect on the MASLD score. Only exercise without fiber decreased the hepatic expression of inflammatory markers. Fiber diet was mainly responsible for remodeling the gut microbial composition, with an increase in the relative abundance of the short-chain fatty acid (SCFA)-producing genera <i>Anaerostipes</i> and <i>Muribaculaceae</i>, whereas, surprisingly, exercise training alone and with fiber resulted in the highest increase of SCFA production. Overall, the combination of exercise training and dietary fiber decreases fat mass and improves glucose and lipid homeostasis but does not have an additional synergistic positive effect on liver health compared with exercise training alone.<b>NEW & NOTEWORTHY</b> The combination of dietary fiber intake and exercise training has a synergetic beneficial effect on the metabolic health, resulting in fat loss, lowered blood glucose, and lowered plasma lipid levels in mice with steatotic liver disease. However, fiber supplementation, despite a positive remodulation of the gut-liver axis, does not have an additional positive effect on liver health compared with exercise training alone.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G399-G410"},"PeriodicalIF":3.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inhibition of hedgehog signaling ameliorates severity of chronic pancreatitis in experimental mouse models.","authors":"Srikanth Iyer, Mohammad Tarique, Preeti Sahay, Sagnik Giri, Ejas P Bava, JiaShiung Guan, Tejeshwar Jain, Utpreksha Vaish, Xiuwen Jin, Sabrina Moon, David K Crossman, Vikas Dudeja","doi":"10.1152/ajpgi.00212.2024","DOIUrl":"10.1152/ajpgi.00212.2024","url":null,"abstract":"<p><p>Chronic pancreatitis (CP) is a fibro-inflammatory disease of the pancreas with no specific cure. Research highlighting the pathogenesis and especially the therapeutic aspect remains limited. Aberrant activation of developmental pathways in adults has been implicated in several diseases. Hedgehog pathway is a notable embryonic signaling pathway, known to promote fibrosis of various organs when overactivated. The aim of this study is to explore the role of the hedgehog pathway in the progression of CP and evaluate its inhibition as a novel therapeutic strategy against CP. CP was induced in mice by repeated injections of l-arginine or caerulein in two separate models. Mice were administered with the FDA-approved pharmacological hedgehog pathway inhibitor, vismodegib during or after establishing the disease condition to inhibit hedgehog signaling. Various parameters of CP were analyzed to determine the effect of hedgehog pathway inhibition on the severity and progression of the disease. Our study shows that hedgehog signaling was overactivated during CP and its inhibition was effective in improving the histopathological parameters associated with CP. Vismodegib administration not only halted the progression of CP but was also able to resolve already-established fibrosis. In addition, inhibition of hedgehog signaling resulted in the reversal of pancreatic stellate cell activation ex vivo. Findings from our study justify conducting clinical trials using vismodegib against CP and, thus, could lead to the development of a novel therapeutic strategy for the treatment of CP.<b>NEW & NOTEWORTHY</b> Hedgehog signaling is activated in human and experimental models of CP. Inhibition of hedgehog signaling using an FDA-approved inhibitor, vismodegib, leads to the resolution of fibrosis and improves CP. This study has immense and immediate translational benefits.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G342-G363"},"PeriodicalIF":3.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142581808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Progesterone sulfates are enterohepatically recycled and stimulate G protein-coupled bile acid receptor 1-mediated gut hormone release.","authors":"Alice L Mitchell, Iain R Tough, Hei Man Fan, Anita Lövgren-Sandblom, Caroline Ovadia, Jenny Chambers, Patricia Fonseca Pedro, Anastasia Tsakmaki, Gavin A Bewick, Hanns-Ulrich Marschall, Helen M Cox, Catherine Williamson","doi":"10.1152/ajpgi.00211.2024","DOIUrl":"10.1152/ajpgi.00211.2024","url":null,"abstract":"<p><p>Sulfated progesterone metabolites (PMxSs) increase during gestation and are raised further in intrahepatic cholestasis of pregnancy (ICP), a disorder characterized by pruritus and elevated serum bile acids. PMxSs interact with bile acid receptor G protein-coupled bile acid receptor 1 (GPBAR1) to cause itch. We investigated whether PMxS could undergo enterohepatic recycling and stimulate intestinal GPBAR1-mediated release of gut hormones glucagon-like peptide-1 (GLP-1) and peptide YY (PYY). PMxSs were quantified in pre-/postprandial serum samples (<i>n</i> = 21) and feces (<i>n</i> = 18) by ultra performance liquid chromatography-tandem mass spectrometry in prospectively recruited third trimester of pregnancy outpatients with uncomplicated pregnancy or ICP. Ussing chambers were used to evaluate colonic ion secretion changes (Δ<i>I</i>_sc) in wildtype, <i>GPBAR1</i>^-/-, and <i>PYY</i>^-/- mice by PMxS metabolites, 5β-pregnan-3α,-20α-diol-3-sulfate (PM3S) and 5α-pregnan-3β-ol-20-one-sulfate (PM5S), and in wildtype mice with or without apical sodium bile acid transporter (ASBT) inhibition (<i>n</i> = 6/condition). PM3S/PM5S stimulation of GLP-1 release from wildtype and <i>GPBAR1</i>^-/- murine crypts and human colonoids was measured by ELISA (<i>n</i> = 3). Serum PMxSs increase postprandially in women with ICP but are unaltered in uncomplicated pregnancies. PMxSs are present in feces. Apical and basolateral PM3S and PM5S stimulated PYY-mediated -Δ<i>I</i>_sc in wildtype (<i>P</i> < 0.01) but not <i>GPBAR1</i>^-/- or <i>PYY</i>^-/- colons. PM3S and PM5S caused GLP-1 secretion in murine crypts and human colonoids (<i>P</i> < 0.001). ASBT inhibition blunted -Δ<i>I</i>_sc by 68% after apical PM3S and PM5S addition (<i>P</i> < 0.001). Serum PMxS, elevated in women with ICP and particularly postprandially, can undergo ASBT-mediated intestinal reuptake and activate GPBAR1 to stimulate gut hormone release. PMxS may therefore augment GPBAR1-mediated metabolic responses during pregnancy.<b>NEW & NOTEWORTHY</b> Sulfated progesterone species (PMxSs) increase postprandially in women with intrahepatic cholestasis of pregnancy (ICP) but not in women with uncomplicated pregnancy. PMxS can be enterohepatically recycled via active transport from the gut lumen by apical sodium-dependent bile acid transporter (ASBT) and stimulate gut hormone secretion. Active reabsorption of PMxS may play a role in the pruritus suffered by women with ICP. ASBT inhibition is a plausible therapy for ICP-associated pruritus.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G377-G385"},"PeriodicalIF":3.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143063144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unresolved alterations in bile acid composition and dyslipidemia in maternal and cord blood after UDCA treatment for intrahepatic cholestasis of pregnancy.","authors":"Srijani Basu, Sarah G Običan, Enrico Bertaggia, Hannah Staab, M Concepcion Izquierdo, Cynthia Gyamfi-Bannerman, Rebecca A Haeusler","doi":"10.1152/ajpgi.00266.2024","DOIUrl":"10.1152/ajpgi.00266.2024","url":null,"abstract":"<p><p>Intrahepatic cholestasis of pregnancy (ICP) is characterized by elevated plasma bile acid levels. ICP is linked to adverse metabolic outcomes, including a reported increased risk of gestational diabetes. The standard therapeutic approach for managing ICP is treatment with ursodeoxycholic acid (UDCA) and induction of labor before 40 wk of gestation. To investigate bile acid and metabolic parameters after UDCA treatment, we enrolled 12 ICP patients with singleton pregnancies-half with and half without gestational diabetes-and 7 controls. Our study reveals that after UDCA treatment, notwithstanding a reduction in total bile acid and alanine aminotransferase levels, imbalances persist in the cholic acid (CA) to chenodeoxycholic acid (CDCA) ratio in maternal and cord blood plasma. This indicates a continued dysregulation of bile acid metabolism despite therapeutic intervention. Maternal plasma lipid analysis showed a distinct maternal dyslipidemia pattern among patients with ICP, marked by elevated cholesterol levels on VLDL particles and heightened triglyceride concentrations on LDL particles, persisting even after UDCA treatment. Cord plasma lipid profiles in patients with ICP exhibited elevated triglyceride and free fatty acid levels alongside a tendency toward increased β-hydroxybutyrate. The changes in lipid metabolism in both maternal and cord blood correlated with the high CA/CDCA ratio but not total bile acid levels or gestational diabetes status. Understanding the imbalances in maternal and cord bile acid and lipid profiles that persist after standard UDCA therapy provides insights for improving management strategies and mitigating the long-term consequences of ICP.<b>NEW & NOTEWORTHY</b> This study uncovers that despite ursodeoxycholic acid treatment, intrahepatic cholestasis of pregnancy (ICP) is associated with increases in the ratio of cholic acid to chenodeoxycholic acid in both maternal and cord blood, suggesting ongoing dysregulation of bile acid metabolism. The high cholic to chenodeoxycholic acid ratio is correlated with maternal dyslipidemia and high cord blood lipids. These findings may inform more targeted approaches to managing ICP.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G364-G376"},"PeriodicalIF":3.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12053871/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143412801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Key mechanisms in alcohol-associated liver disease: hepatic ADH deficiency, dysregulated hepatic lipid metabolism, and nonoxidative ethanol metabolites.","authors":"Seol Hee Park, Wonhyo Seo","doi":"10.1152/ajpgi.00076.2025","DOIUrl":"10.1152/ajpgi.00076.2025","url":null,"abstract":"","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G426-G428"},"PeriodicalIF":3.9,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143584377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DIFFERENTIAL RESPONSES TO PROSTAGLANDINS IN THE CIRCULAR AND LONGITUDINAL MUSCLE LAYERS OF THE MURINE ILEUM.","authors":"Joong Goo Kwon, Sung Jin Hwang, Elizabeth A H Beckett, Kenton M Sanders, Sean Ward","doi":"10.1152/ajpgi.00400.2024","DOIUrl":"https://doi.org/10.1152/ajpgi.00400.2024","url":null,"abstract":"<p><p>Prostaglandin E₂ (PGE₂) actions on intestinal motility are complex due the differential expression of the PGE₂ receptors EP1-EP4. We sought to determine the actions of PGE₂ on electrical pacemaker and contractile activity of the circular and longitudinal muscle layers of the murine small intestine. Intracellular microelectrode and isometric force measurements were performed to examine the effects of PGE₂ receptor activation on circular and longitudinal muscle layers. In the two muscle layers PGE₂ produced differential responses. In the circular muscle layer PGE₂ caused dose-dependent membrane hyperpolarization and reduction in slow wave amplitude, accompanied by a decrease in the amplitude of phasic contractions. Membrane hyperpolarization and the reduction in slow wave amplitude and phasic contractions were insensitive to TTX and L-NNA, but inhibited by the K_ATP channel antagonist, glibenclamide. The actions of PGE₂ on the circular muscle layer were mimicked by the selective EP₂ and EP₄ agonists ONO AE1-259 and ONO AE1-329, respectively. The actions of PGE₂ were partially inhibited by the EP4 antagonist ONO AE3-208. The EP₁ agonist ONO DI-004 produced little effect while the EP3 agonist ONO AE-248 caused dose-dependent membrane depolarization. In comparison, PGE₂ produced increased tone and phasic contractions in the longitudinal muscle layer that was mimicked by ONO DI-004 and ONO AE-248, while EP₂ and EP₄ agonists had little effect on contractile activity. These data suggest that differential expression of PGE₂ receptors on intestinal muscle layers can produce antagonistic actions on intestinal motility.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143565583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}