Duodenal Fluid Research Articles

Supersaturation and Precipitation of Posaconazole Upon Entry in the Upper Small Intestine in Humans

The purpose of this study was to explore gastrointestinal dissolution, supersaturation and precipitation of the weakly basic drug posaconazole in humans, and to assess the impact of formulation pH and type on these processes. In a cross-over study, two posaconazole suspensions (40 mg dispersed in 240 mL water at pH 1.6 and pH 7.1, respectively) were intragastrically administered; subsequently, gastric and duodenal fluids were aspirated. In parallel, blood samples were collected. Additionally, posaconazole was intragastrically administered as a solution (20 mg in 240 mL water, pH 1.6). When posaconazole was administered as an acidified suspension, supersaturated duodenal concentrations of posaconazole were observed for approximately 45 min. However, extensive intestinal precipitation was observed. Administration of the neutral suspension resulted in subsaturated concentrations with a mean duodenal AUC0-120 min and Cmax being approximately twofold lower than for the acidified suspension. The mean plasma AUC0-8 h of posaconazole was also twofold higher following administration of the acidified suspension. Similar to the acidified suspension, significant intestinal precipitation (up to 92%) was observed following intragastric administration of the posaconazole solution. This study demonstrated for the first time the gastrointestinal behavior of a weakly basic drug administered in different conditions, and its impact on systemic exposure.

Ethanol concentrations in the human gastrointestinal tract after intake of alcoholic beverages

IntroductionThe goal of this study was to monitor gastric and duodenal ethanol concentrations arising from the consumption of commonly used alcoholic beverages. Materials and methodsIn a cross-over study, five fasting volunteers were asked to drink two standard consumptions of commercially available alcoholic beverages, including beer (Stella Artois®, 500mL, 5.2% ethanol), wine (Blanc du Blanc®, 200mL, 11% ethanol) and whisky (Gallantry Whisky®, 80mL, 40% ethanol). The volunteers finished drinking beer within 10min and wine or whisky within 5min. Ethanol concentrations in gastric and duodenal fluids, aspirated as a function of time, were analyzed by headspace gas chromatography. ResultsIn all three conditions, the average gastric profile shows a maximum ethanol concentration (Cmax) at 7min, while the mean duodenal profiles have a Tmax at 20, 7 and 12min for beer, wine and whisky, respectively. The median gastric ethanol Cmax (min–max) for the beer, wine and whisky conditions amounts to 4.1% (3.1–4.1), 4.1% (2.6–7.3) and 11.4% (6.3–21.1), respectively. The mean duodenal profiles follow the same pattern as their corresponding gastric profiles, albeit with lower percentages of ethanol. Median duodenal ethanol Cmax (min–max) for beer, wine and whisky are 1.97% (0.89–4.3), 2.39% (2.02–5.63) and 5.94% (3.55–17.71), respectively. Intraluminal ethanol concentrations appear to decline relatively rapidly in fasting conditions: both stomach and duodenum contained less than 0.05% of ethanol after 120min. ConclusionsThis in vivo study is the first to present intraluminal ethanol concentrations in man after the intake of alcoholic beverages. Relatively low and fast declining gastric ethanol concentrations were observed, contrasting with the current Food and Drug Administration guidelines for the in vitro testing of formulations with respect to ethanol resistance. The presented gastric and duodenal ethanol concentrations and their variation may serve as reference data to design relevant models for predicting (i) ethanol resistance of drug formulations and (ii) ethanol effects on drug solubility and permeability.

Characterization of Human Duodenal Fluids in Fasted and Fed State Conditions

This work provides an elaborate characterization of human intestinal fluids (HIF) collected in fasted- and fed-state conditions. HIF from 20 healthy volunteers (10 M/F) were aspirated by intubation near the ligament of Treitz in a time-dependent manner (10-min intervals) and characterized for pH, bile salts, phospholipids, cholesterol, triacylglycerides (TAG), diacylglycerides (DAG), monoacylglycerides (MAG), free fatty acids (FFA), pancreatic lipase, phospholipase A2, and nonspecific esterase activity. For almost all parameters, a food-induced effect was observed. Results were characterized by a high variability, as illustrated by the broad ranges observed for each parameter: pH (fasted: 3.4-8.3; fed: 4.7-7.1), bile salts (fasted: 0.03-36.18 mM; fed: 0.74-86.14 mM), phospholipids (fasted: 0.01-6.33 mM; fed: 0.16-14.39 mM), cholesterol (fasted: 0-0.48 mM; fed: 0-3.29 mM), TAG (fed: 0-6.76 mg/mL), DAG (fed: 0-3.64 mg/mL), MAG (fasted: 0-1.09 mg/mL; fed: 0-11.36 mg/mL), FFA (fasted: 0-3.86 mg/mL; fed: 0.53-15.0 mg/mL), pancreatic lipase (fasted: 26-86 g/mL; fed: 146-415 g/mL), phospholipase A2 (fasted: 3-6 ng/mL; fed: 4.3-27.7 ng/mL), and nonspecific esterase activity (fasted: 270-4900 U/mL; fed: 430-4655 U/mL). This comprehensive overview may serve as reference data for physiologically based pharmacokinetic modeling and the optimization of biorelevant simulated intestinal fluids for the use in in vitro dissolution, solubility, and permeability profiling.

Small intestinal bacterial overgrowth and toll-like receptor signaling in patients with non-alcoholic fatty liver disease.

The pathogenesis of non-alcoholic fatty liver disease (NAFLD) is multifactorial. There is sparse literature on the role of small intestinal bacterial overgrowth (SIBO) and toll-like receptor (TLR) signaling in NAFLD. The present study evaluated the relationship of SIBO with expression of TLR signaling genes in patients with NAFLD. A total of 142 subjects composed of NAFLD (n = 60, mean age 38.7 ± 10.4 years), chronic viral hepatitis (CVH) (n = 32, mean age 39.5 ± 10.6 years), and healthy volunteers (n = 50, mean age 36.56 ± 4.2 years) were enrolled in the study. Duodenal fluid was taken endoscopically in 32 prospective patients with NAFLD for evaluation of SIBO. Hepatic mRNA expression of TLR4, CD14, TLR2, NF-κβ, and MD2 and protein expression of TLR4 and TLR2 were studied in 64 patients (NAFLD = 32, CVH = 32) by RT-PCR and immunohistochemistry, respectively. Serum levels of TNF-α, adiponectin, insulin, and endotoxins were also evaluated. Small intestinal bacterial overgrowth was present in 12 (37.5%) out of 32 patients with NAFLD with Escherichia coli as the predominant bacterium. In comparison with those without SIBO, patients with SIBO had significantly higher endotoxin levels and higher CD14 mRNA, nuclear factor kappa beta mRNA, and TLR4 protein expression. Patients with NASH had significantly higher endotoxin levels and higher intensity of TLR4 protein expression in comparison with patients without NASH. Serum levels of TNF-α, endotoxins, and insulin were significantly higher and of adiponectin lower in NAFLD in comparison with CVH and healthy volunteers. Our study provides the first direct evidence of role of SIBO and endotoxemia and its relation with TLR signaling genes and liver histology in patients with NAFLD.

Natural Inhibitors of Lipase: Examining Lipolysis in a Single Droplet.

Inhibition of lipase activity is one of the approaches to reduced fat intake with nutritional prevention promoting healthier diet. The food industry is very interested in the use of natural extracts, hence reducing the side effects of commercial drugs inhibiting lipolysis. In this work we propose a novel methodology to rapidly assess lipolysis/inhibition in a single droplet by interfacial tension and dilatational elasticity. The evolution of the interfacial tension of lipase in simplified duodenal fluid in the absence and that in the presence of the pharmaceutical drug Xenical are the negative (5 ± 1 mN/m) and positive (9 ± 1 mN/m) controls of the inhibition of lipolysis, respectively. Then, we correlate the inhibition with the reduction of the interfacial activity of lipase and further identify the mode of action of the inhibition based on dilatational response (conformational changes induced in the molecule/blocking of adsorption sites). This work provides new insight into the lipase inhibition mechanism and a rapid methodology to identify the potential of new natural inhibitors.

Duodenal microbiota is not the predominent origin for bacterial translocation in liver cirrhosis

Background and aims: Intestinal dysbiosis and bacterial translocation (BT) in cirrhosis has been regarded as the main driver for infections. However, results regarding the intestinal origin of BT are conflicting. Although the small intestine has been considered having the greatest potential for BT further results promoted that bacteria mainly translocate from the colon. We therefore investigated duodenal fluid and blood of patients with cirrhosis in terms of its bacterial DNA (bactDNA) content and composition.

Effect of dietary supplementation of rutin on lactation performance, ruminal fermentation and metabolism in dairy cows.

The effect of long-term dietary supplementation with rutin on the lactation performance, ruminal fermentation and metabolism of dairy cows were investigated in this study. Twenty multiparous Chinese Holstein cows were randomly divided into four groups, and each was offered a basal diet supplemented with 0, 1.5, 3.0 or 4.5 mg rutin/kg of diet. The milk yield of the cows receiving 3.0 and 4.5 mg rutin/kg was higher than that of the control group, and the milk yield was increased by 10.06% and 3.37% (p < 0.05). On the basis of that finding, the cows supplemented with 0 or 3.0 mg rutin/kg of diet were used to investigate the effect of rutin supplementation on blood metabolites and hormone levels. Compared with the control group, the serum blood urea nitrogen (BUN) concentration of the 3.0 mg rutin/kg group is significantly decreased (p < 0.05). In another trial, four adult cows with permanent rumen fistula and duodenal cannulae were attributed in a self-control design to investigate the peak occurrence of rutin and quercetin in different parts of the gastrointestinal tract, ruminal fermentation and microbial population in dairy cows. The cows supplemented with 3.0 mg rutin/kg in the diet differed from the control period. Samples of rumen fluid, duodenal fluid and blood were collected at 1, 2, 3, 4, 5, 6, 7 and 8 h after morning feeding. Compared to the control group, the pH, ammonia nitrogen concentration, number and protein content of rumen protozoa and blood urea nitrogen were lower, but the concentration of total volatile fatty acid (TVFA), microbial crude protein (MCP) and serum lysozyme content were higher for the cows fed the rutin diets. The addition of 3.0 mg rutin/kg to diets for a long term tended to increase the milk yield and improve the metabolism and digestibility of the dairy cows.

760 Confocal Endomicroscopy Demonstrates Increased Intestinal Permeability and Gut Dysfunction in Patients With Acute and Chronic Pancreatitis

Introduction Increased intestinal permeability and endotoxaemia occur in acute pancreatitis (AP) but have yet to be confirmed in chronic pancreatitis (CP). Confocal endomicroscopy (CEM) is a novel technology that has identified epithelial gaps and leakage of intravenously administered fluorescein from small intestinal mucosa in inflammatory bowel diseases. We aimed to determine intestinal permeability changes in AP and CP using CEM, assessing associations with endotoxaemia, circulating cytokines and alterations in duodenal flora. Method 182 patients were recruited: 35 mild AP; 11 moderate AP; 8 severe AP (Determinant Based Classification); 47 CP (27 surgically managed, 20 conservatively managed); 33 chronic liver disease and 48 non-ulcer dyspepsia (from whom 14 healthy H. pylorinegative controls were identified). Blood was sampled and duodenal fluid aspirated for culture. CEM was performed in consenting patients and fluorescein leakage scored by two independent blinded investigators. Plasma endotoxin antibodies, serum cytokine concentrations and lactulose:mannitol ratios were measured; D-amino oxidase concentrations were assayed in AP patients undergoing CEM. Results Fluorescein leakage from epithelial villi at CEM and lactulose:mannitol ratios were significantly higher in AP patients (p = 0.0346 and p = 0.046 respectively) and surgically managed CP (p = 0.032, p = 0.030) compared to healthy controls. Patients with AP more frequently showed positive duodenal bacterial cultures than controls (p = 0.004); positive duodenal cultures were associated with fluorescein leakage (p = 0.035). Plasma IgM and IgG concentrations were decreased in AP compared to controls, most markedly in severe AP, and multiple cytokines showed significantly increased concentrations in severe AP. D-amino oxidase enzyme concentrations were significantly increased in those AP patients who showed fluorescein leakage at CEM (p = 0.035). Conclusion CEM identified increased intestinal permeability in AP and surgically managed CP, associated with endotoxaemia, increased serum inflammatory cytokines and D-amino oxidase. These changes were most marked in severe AP. The association of fluorescein leakage with duodenal bacterial proliferation in AP indicates major gut dysfunction that may account for bacterial translocation via epithelial gaps, contributing to AP severity. Disclosure of interest None Declared.

Short communication: Difructose anhydride III promotes calcium absorption from the duodenum in cattle

Difructose anhydride (DFA) III promotes the intestinal absorption of calcium via a paracellular pathway in rats. In dairy cows, DFA III reaches the duodenum without being degraded by ruminal bacteria and hence could be used to control hypocalcemia. The aims of the present study were to investigate the percentage of DFA III that appears in the duodenum of cows and to determine the effect of DFA III on calcium absorption from duodenal fluid. The first experiment was performed in 3 ruminally and duodenally cannulated dry Holstein cows in a 3×3 Latin square design. Each experimental period lasted 7 d. On the first day, the cows were ruminally fed one of the following treatments: 0 (DFA0), 50 (DFA50), or 100 (DFA100) g/d of DFA III, using cobalt-EDTA as a liquid phase marker. Difructose anhydride III was detected in duodenal fluid 1 h after feeding, and its concentration peaked 4 h after feeding, in a dose-dependent manner. The percentages of DFA III that appeared in the duodenum after the DFA50 and DFA100 treatments were 69.1±7.0% and 67.9±5.6%, respectively. The second experiment used the everted duodenal sacs of cattle (n=7 in each group). Sacs were incubated in artificial mucosal fluid containing 1 mM DFA III or no DFA III (control) for 60min with 100% O2 in a water bath at 37°C. After incubation, the calcium concentration of the artificial serosal fluid in the everted sacs was measured. Calcium absorption was higher in the DFA III-treated group than in the control group (803±161 and 456±74 nmol/cm of sac, respectively). The above results demonstrate that approximately 70% of administered DFA III reached the duodenum of cows intact. Moreover, similar to its effects on calcium absorption in rats, DFA III promoted calcium absorption via a paracellular pathway in the duodenum of cows.

Diagnostic accuracy of secretin-stimulated ultrasonography of the pancreas assessing exocrine pancreatic failure in cystic fibrosis and chronic pancreatitis

Objective. Volume output failure is a feature of decreasing exocrine pancreatic function. This parameter is assessed by secretin-stimulated MRI in several studies. Our purpose was to evaluate ultrasonography of the fluid in the descending duodenum and Wirsung duct (WD) after secretin stimulation as a measure of pancreatic fluid flow in patients expected to have severe output failure. Material and methods. We included subjects with chronic pancreatitis (CP), cystic fibrosis (CF) and a group of healthy controls in a prospective observation study. Transabdominal ultrasonography was performed before and during 15 min after secretin i.v. duodenal juice was collected by endoscopic short test (EST), and bicarbonate concentration measured. Patient groups were classified according to exocrine pancreatic function. Results. Pancreatic insufficient CF (CFI) patients and CP insufficient (CPI) patients showed less duodenal fluid filling compared to other groups (p < 0.001). Measures of the WD diameter could only identify the most severe failure in the CFI group (p < 0.001). Conclusion. Secretin-stimulated ultrasonography can be used to assess pancreatic fluid flow and may be combined with EST in the evaluation of exocrine pancreatic function. Fluid filling in the descending part of duodenum was the most accurate predictor of pancreatic insufficiency in both patient groups. The test demonstrated better diagnostic accuracy diagnosing exocrine pancreatic failure in the CF patients than in CP patients.

Rapid conversion of the ester prodrug abiraterone acetate results in intestinal supersaturation and enhanced absorption of abiraterone: In vitro, rat in situ and human in vivo studies

The aim of this study was to evaluate the intestinal disposition of abiraterone acetate, an ester prodrug of the anticancer agent abiraterone. Stability of the prodrug and solubility and dissolution characteristics of both abiraterone and abiraterone acetate were monitored in vitro. Moreover, the in vivo intraluminal concentrations of abiraterone and abiraterone acetate upon intake of one tablet of 250mg abiraterone acetate were assessed in healthy volunteers. The intestinal absorption resulting from the intraluminal behavior of the ester prodrug was determined using the rat in situ intestinal perfusion technique with mesenteric blood sampling. Simulated and aspirated human intestinal fluids of the fasted state were used as solvent systems.Upon incubation of abiraterone acetate in human intestinal fluids in vitro, rapid hydrolysis of the prodrug was observed, generating abiraterone concentrations largely exceeding the apparent solubility of abiraterone, suggesting the existence of intestinal supersaturation. These findings were confirmed in vivo, by intraluminal sampling of duodenal fluids upon oral intake of an abiraterone acetate tablet by healthy volunteers.Rat in situ intestinal perfusion experiments performed with suspensions of abiraterone and abiraterone acetate in human intestinal fluids of the fasted state revealed significantly higher flux values upon perfusion with the prodrug than with abiraterone. Moreover, rat in situ intestinal perfusion with abiraterone acetate suspensions in simulated fluids of the fasted state in presence or absence of esterases demonstrated that increased hydrolytic activity of the perfusion medium was beneficial to the intestinal absorption of abiraterone.In conclusion, the rapid hydrolysis of abiraterone acetate in the intraluminal environment appears to result in fast and extensive generation of abiraterone supersaturation, creating a strong driving force for abiraterone absorption.

Comparative Study of Pineapple Juice as a Negative Oral Contrast Agent in Magnetic Resonance Cholangiopancreatography

The aim of this study was to compare the image quality of magnetic resonance Cholangiopancreatography (MRCP) using Pineapple Juice (PJ) or ranitidine as negative oral contrast agents and no agent. MRCP images of patients administered PJ (n = 117) or Ranitidine (n = 110) at random, and patients without an agent (n = 50) were evaluated. The subjective image quality of the overall, extra hepatic bile duct and pancreatic duct and the degree of elimination of gastrointestinal fluid were scored by two blinded radiologists. RESULTS were compared using Mann-Whitney's U-test. The degrees of elimination of gastro duodenal fluid of PJ and ranitidine were significantly better than those without an agent (p < 0.01 and p < 0.01, respectively). The subjective image quality of PJ of the overall and extra hepatic bile duct were significantly better, although no significant differences for ranitidine were observed compared with those without an agent (p < 0.01 and p =0.23, p = 0.025 and p = 0.18). There were no significant differences for the pancreatic duct (p = 0.13 and p = 0.20), nor were there any significant differences in the evaluations between PJ and ranitidine (p = 0.21 and p = 0.96). PJ showed better performance compared to that of conventional ranitidine in terms of pancreatic and biliary depiction and safety.

Mutant KRAS and GNAS DNA Concentrations in Secretin-Stimulated Pancreatic Fluid Collected from the Pancreatic Duct and the Duodenal Lumen.

Objectives:The analysis of secretin-stimulated pancreatic fluid is being evaluated as an approach to improve the early detection of pancreatic cancer and pancreatic precursor neoplasms. The method of pancreatic fluid sampling may have a significant impact on tumor marker measurements. The aim of this study was to compare concentrations of mutant DNA in pancreatic fluid from patients who had samples collected from both the pancreatic duct and duodenal lumen.Methods:Thirty-six participants enrolled in the Cancer of the Pancreas Screening studies at Johns Hopkins Hospital who had secretin-stimulated pancreatic fluid collected from the duodenum during endoscopic ultrasound (EUS) and from the pancreatic duct during subsequent endoscopic retrograde cholangiopancreatography. Mutant KRAS and GNAS DNA concentrations were measured in pancreatic fluid samples using digital high-resolution melt-curve analysis and pyrosequencing and were related total DNA concentrations in these samples.Results:Thirty-four patients had subtle parenchymal abnormalities by EUS; seven had small pancreatic cysts; none had pancreatic cancer. KRAS mutations were detected in 29 of 36 (80.6%) pancreatic duct fluid samples. Of these 29 patients, 23 had mutations detected in their duodenal fluid (79.3%). Patients with detectable pancreatic fluid but not duodenal fluid KRAS mutations had lower average pancreatic duct fluid KRAS mutation concentrations (P=0.01). Patients with KRAS or GNAS mutations detected in pancreatic fluid but not duodenal fluid had higher total DNA concentrations in their duodenal compared with pancreatic fluid (P=0.03). KRAS and GNAS mutation concentrations were higher in pancreatic duct fluid samples than in matching duodenal fluid samples (for KRAS: 2.62 vs. 0.39%, P<0.0001).Conclusions:KRAS and GNAS mutation concentrations are significantly lower in secretin-stimulated pancreatic fluid samples collected from the duodenum compared with samples collected from the pancreatic duct. Efforts to improve the purity of pancreatic fluid collections from the duodenum could improve the detection of mutations arising from the pancreas.

Long-term oral melatonin administration reduces ethanol-induced increases in duodenal mucosal permeability and motility in rats.

Increased intestinal epithelial permeability is associated with intestinal inflammation and dysfunction. The aim of the present study was to investigate the role of long-term oral melatonin administration on ethanol-induced increases in duodenal mucosal permeability and hypermotility. Male Sprague-Dawley rats were administered melatonin in their tap water (0.1 mg mL(-1) or 0.5 mg mL(-1) ) for 2 or 4 weeks. After the treatment period, the rats were anaesthetized with Inactin(®) , and a 30-mm duodenal segment was perfused in situ. The effects on duodenal mucosal paracellular permeability, bicarbonate secretion, fluid flux and motor activity were studied. The expression levels of the tight junction components, zona occludens (ZO)-1, ZO-2, and ZO-3, claudin-2, claudin-3, claudin-4, occludin, and myosin light chain kinase and of the melatonin receptors MT1 and MT2 were assessed using qRT-PCR. Melatonin administration for 2 weeks significantly reduced the basal paracellular permeability, an effect that was absent after 4 weeks. Perfusing the duodenal segment with 15% ethanol induced marked increases in duodenal paracellular permeability, bicarbonate secretion and motor activity. Melatonin for 2 weeks dose-dependently reduced ethanol-induced increases in permeability and motor activity. Four weeks of melatonin administration reduced the ethanol-induced increases in duodenal motility and bicarbonate secretion but had no effect on the increases in permeability. Two weeks of melatonin administration upregulated the expression of MT1 and MT2 , although both were downregulated after 4 weeks. Melatonin downregulated the expression of ZO-3 and upregulated the expression of claudin-2, even as all other mRNA-levels investigated were unaffected. Although further studies are needed, our data demonstrate that melatonin administration markedly improves duodenal barrier functions, suggesting its utility in clinical applications when intestinal barrier functions are compromised.

The ethanol-induced stimulation of rat duodenal mucosal bicarbonate secretion in vivo is critically dependent on luminal Cl-.

Alcohol may induce metabolic and functional changes in gastrointestinal epithelial cells, contributing to impaired mucosal barrier function. Duodenal mucosal bicarbonate secretion (DBS) is a primary epithelial defense against gastric acid and also has an important function in maintaining the homeostasis of the juxtamucosal microenvironment. The aim in this study was to investigate the effects of the luminal perfusion of moderate concentrations of ethanol in vivo on epithelial DBS, fluid secretion and paracellular permeability. Under thiobarbiturate anesthesia, a ∼30-mm segment of the proximal duodenum with an intact blood supply was perfused in situ in rats. The effects on DBS, duodenal transepithelial net fluid flux and the blood-to-lumen clearance of 51Cr-EDTA were investigated. Perfusing the duodenum with isotonic solutions of 10% or 15% ethanol-by-volume for 30 min increased DBS in a concentration-dependent manner, while the net fluid flux did not change. Pre-treatment with the CFTR inhibitor CFTRinh172 (i.p. or i.v.) did not change the secretory response to ethanol, while removing Cl− from the luminal perfusate abolished the ethanol-induced increase in DBS. The administration of hexamethonium (i.v.) but not capsazepine significantly reduced the basal net fluid flux and the ethanol-induced increase in DBS. Perfusing the duodenum with a combination of 1.0 mM HCl and 15% ethanol induced significantly greater increases in DBS than 15% ethanol or 1.0 mM HCl alone but did not influence fluid flux. Our data demonstrate that ethanol induces increases in DBS through a mechanism that is critically dependent on luminal Cl− and partly dependent on enteric neural pathways involving nicotinic receptors. Ethanol and HCl appears to stimulate DBS via the activation of different bicarbonate transporting mechanisms.

Fat content and nitrite-curing influence the formation of oxidation products and NOC-specific DNA adducts during in vitro digestion of meat.

The effects of fat content and nitrite-curing of pork were investigated on the formation of cytotoxic and genotoxic lipid oxidation products (malondialdehyde, 4-hydroxy-2-nonenal, volatile simple aldehydes), protein oxidation products (protein carbonyl compounds) and NOC-specific DNA adducts (O6-carboxy-methylguanine) during in vitro digestion. The formation of these products during digestion is suggested to be responsible for the association between red meat and processed meat consumption and colorectal cancer risk. Digestion of uncured pork to which fat was added (total fat content 5 or 20%), resulted in significantly higher lipid and protein oxidation in the mimicked duodenal and colonic fluids, compared to digestion of pork without added fat (1% fat). A higher fat content also significantly favored the formation of O6-carboxy-methylguanine in the colon. Nitrite-curing of meat resulted in significantly lower lipid and protein oxidation before and after digestion, while an inconsistent effect on the formation of O6-carboxy-methylguanine was observed. The presented results demonstrate that haem-Fe is not solely responsible for oxidation and nitrosation reactions throughout an in vitro digestion approach but its effect is promoted by a higher fat content in meat.

Accumulation of monepantel and its sulphone derivative in tissues of nematode location in sheep: Pharmacokinetic support to its excellent nematodicidal activity

The amino-acetonitrile derivatives (AADs) are a new class of anthelmintic molecules active against a wide range of sheep gastrointestinal (GI) nematodes including those that are resistant to other anthelmintic families. The plasma disposition of monepantel (MNP) has been previously characterized in sheep. However, information on drug concentration profiles attained at tissues of parasite location is necessary to fully understand the pharmacological action of this novel compound. The current work aimed to study the relationship between the concentrations of MNP parent drug and its main metabolite monepantel sulphone (MNPSO2), measured in the bloodstream and in different GI tissues of parasite location in sheep. Twenty two (22) uninfected healthy Romney Marsh lambs received MNP (Zolvix®, Novartis Animal Health) orally administered at 2.5mg/kg. Blood samples were collected from six animals between 0 and 14 days post-treatment to characterize the drug/metabolite plasma disposition kinetics. Additionally, 16 lambs were sacrificed at 8, 24, 48 and 96h post-administration to assess the drug concentrations in the GI fluid contents and tissues. MNP and MNPSO2 concentrations were determined by HPLC. MNP parent compound was rapidly oxidized into MNPSO2. MNP systemic availability was significantly lower than that observed for MNPSO2. The peak plasma concentrations were 15.1 (MNP) and 61.4ng/ml (MNPSO2). The MNPSO2 to MNP plasma concentration profile ratio (values expressed in AUC) reached a value of 12. Markedly higher concentrations of MNP and MNPSO2 were measured in both abomasal and duodenal fluid contents, and mucosal tissues compared to those recovered from the bloodstream. A great MNP availability was measured in the abomasal content with concentration values ranging between 2000 and 4000ng/g during the first 48h post-treatment. Interestingly, the metabolite MNPSO2 was also recovered in abomasal content but its concentrations were significantly lower compared to MNP. The parent drug and its sulphone metabolite were detected in the different segments of the sheep intestine. MNPSO2 concentrations in the different intestine sections sampled were significantly higher compared to those measured in the abomasum. Although MNP is metabolized to MNPSO2 in the liver, the large concentrations of both anthelmintically active molecules recovered during the first 48h post-treatment from the abomasum and small intestine may greatly contribute to the well-established pharmacological activity of MNP against GI nematodes.

Carboxyl-Ester Lipase Maturity-Onset Diabetes of the Young Is Associated With Development of Pancreatic Cysts and Upregulated MAPK Signaling in Secretin-Stimulated Duodenal Fluid

Carboxyl-ester lipase (CEL) maturity-onset diabetes of the young (MODY) is a monogenic form of diabetes and pancreatic exocrine dysfunction due to mutations in the CEL gene encoding CEL. The pathogenic mechanism for diabetes development is unknown. Since CEL is expressed mainly in pancreatic acinar cells, we asked whether we could find structural pancreatic changes in CEL-MODY subjects during the course of diabetes development. Furthermore, we hypothesized that the diseased pancreas releases proteins that are detectable in pancreatic fluid and potentially reflect activation or inactivation of disease-specific pathways. We therefore investigated nondiabetic and diabetic CEL-mutation carriers by pancreatic imaging studies and secretin-stimulated duodenal juice sampling. The secretin-stimulated duodenal juice was studied using cytokine assays, mass spectrometry (MS) proteomics, and multiplexed MS-based measurement of kinase activities. We identified multiple pancreatic cysts in all eight diabetic mutation carriers but not in any of the four nondiabetic mutation carriers or the six healthy controls. Furthermore, we identified upregulated mitogen-activated protein kinase (MAPK) target proteins and MAPK-driven cytokines and increased MAPK activity in the secretin-stimulated duodenal juice. These findings show that subjects with CEL-MODY develop multiple pancreatic cysts by the time they develop diabetes and that upregulated MAPK signaling in the pancreatic secretome may reflect the pathophysiological development of pancreatic cysts and diabetes.

Prevention of duodenal ileus reveals functional differences in the duodenal response to luminal hypertonicity in Sprague‐Dawley and Dark Agouti rats

The mechanism by which the duodenum adjusts the luminal osmolality remains unclear. The aim was to compare the duodenal osmoregulation in response to different hyperosmolar solutions in Sprague-Dawley and Dark Agouti rats and to elucidate whether cyclooxygenase-2 inhibition affects these responses. The duodenum was perfused in situ with a 700-milliosmolar solution (NaCl alone, D-glucose ± NaCl, D-mannitol ± NaCl or orange juice), and the effects on the duodenal motility, mucosal permeability, luminal alkalinization, fluid flux and osmoregulation were assessed in anaesthetized rats. The change in net fluid flux and luminal osmolality, in response to a given hyperosmolar solution, was almost identical in control rats of both strains. In control rats, hypertonic D-glucose-NaCl induced fluid secretion only in the presence of phlorizin, an inhibitor of SGLT1. Cyclooxygenase-2 inhibition potentiated the hypertonicity-induced fluid secretion and increased the osmolality-adjusting capability in both strains, but the responses were greater in Dark Agouti rats. While cyclooxygenase-2-inhibited Dark Agouti rats responded to the hyperosmolar solutions with depression of motility and increased mucosal permeability, these effects were absent or smaller in the Sprague-Dawley strain. In contrast, orange juice induced the same duodenal responses in cyclooxygenase-2-inhibited Dark Agouti and Sprague-Dawley rats. The duodenum possesses the ability to absorb fluid despite a very high luminal osmolality. Inhibition of cyclooxygenase-2 markedly enhanced the capability of the duodenum to secrete fluid and to decrease luminal osmolality, irrespective of the hyperosmolar solution or the rat strain used, and revealed notable differences between the two strains with regard to their osmolality-adjusting capability.

Magnets in the GI tract

Magnets in the GI tract