Duodenal Level Research Articles

Effects of a dietary isoquinoline alkaloids blend on gut antioxidant capacity and gut barrier of young broilers

Extensive mechanistic evidence to support the beneficial function of dietary phytobiotic applications for broiler performance, gut function and health is highly warranted. In particular, for isoquinoline alkaloids (IQ) the underlying mechanisms related to critical gut homeostasis components such as cytoprotection and gut barrier are scarce, especially for young broilers at the starter growth stage (d1-10). The aim of this study was to investigate the effect of a standardized blend of IQs on the relative gene expression of critical biomarkers relevant for antioxidant response and barrier function along the intestine of young broilers at the end of starter growth phase. For this purpose, 182 one-day-old Ross 308 broilers were allocated in 2 treatments with 7 replicates of 13 broilers each: control diet-no other additions (NC), and control diet containing a standardized blend of IQs at 200 mg/kg of diet (M) for the starter growth period (1-10d). The results revealed that the IQs blend significantly upregulated (P < 0.05) the expression of genes related to antioxidant response in all intestinal segments. Moreover, the IQs blend enhanced (P < 0.05) gut barrier components primarily at duodenal level. In conclusion, the blend of IQs beneficially affected critical pathway components relevant for the gut antioxidant capacity and barrier along the intestine of young broilers.

Intestinal Morphometric Changes Induced by a Western-Style Diet in Wistar Rats and GSPE Counter-Regulatory Effect.

Western-style diet is an obesogenic diet for rodents and humans due to its content of saturated fat and refined sugars, mainly sucrose and, in consequence, sucrose-derived fructose. This type of diets relates with intestinal disturbances when consumed regularly. The aim of this work was to analyse the adaptive morphologic and functional changes at intestinal level derived from the unhealthy components of a Cafeteria diet in rats. The effect of grape seed proanthocyanidin extract (GSPE) in the prevention of diet-induced intestinal dysfunction was also analysed. Rats were fed a 17-week cafeteria diet (CAF) without or with oral-GSPE supplementation, either intermittent GSPE administration (SIT-CAF); last 10-day GSPE supplementation at doses of 100 mg/kg and 500 mg/kg day (CORR-100) and (CORR-500) or pre-supplementation with 500 mg/kg GSPE (PRE-CAF). GSPE-CAF supplemented groups showed similar results to CAF diet group regarding morphology and inflammatory score in the duodenum. As an adaptive response to diet, CAF increased intestinal absorptive surface (1.24-fold) all along the intestinal tract and specifically in the small intestine, duodenum, due to increase villus height and a higher villus/crypt ratio, in addition to increase in Goblet cell percentage and inflammatory index. Animals fed GSPE at the current doses and times had higher villus heights and absorptive surface similar to Cafeteria diet group. In the duodenum, villus height correlated with body weight at 17 week and negatively with MLCK gene expression. In the colon, villus height correlated with the percentage of goblet cells. In conclusion, the CAF diet produced adaptive modifications of the intestine by increasing the absorptive area of the small intestine, the percentage of goblet cells and the inflammatory index at the duodenal level. GSPE supplementation can partially reverse the intestinal morphological changes induced by the high fat/sucrose diet when administered intermittently.

Levothyroxine Therapy in Gastric Malabsorptive Disorders.

Oral levothyroxine sodium is absorbed in the small intestine, mainly in the jejunum and the ileum being lower the absorption rate at duodenal level. The time interval between the ingestion of oral thyroxine and its appearance in the plasma renders unlike a gastric absorption of the hormone. However, several evidence confirm the key role of the stomach as a prerequisite for an efficient absorption of oral levothyroxine. In the stomach, in fact, occur key steps leading to the dissolution of thyroxine from the solid form, the process bringing the active ingredient from the pharmaceutical preparation to the aqueous solution. In particular, gastric juice pH, volume, viscosity, as well as gastric emptying time seem to be the most important limiting factors. These hypotheses are confirmed by the detection of an increased need for levothyroxine in patients with Helicobacter pylori infection, chronic atrophic gastritis, gastroparesis, or in simultaneous treatment with drugs interfering with gastric acidic output. The aim of the present article is to focus on the knowledge of pathophysiologic events that determine the absorptive fate of traditional (tablet) and alternative thyroxine preparations (softgel capsule and liquid solution) in patients bearing gastric disorders.

In Vivo Digestion of Egg Products Enriched with DHA: Effect of the Food Matrix on DHA Bioavailability.

The aim of the present study was to determine to what extent the food matrix could affect the release of docosahexaenoic acid (DHA) during digestion and its incorporation into systemic circulation. In this aim, three DHA-enriched egg products having the same composition but different structure were developed: omelet, hard-boiled egg, and mousse. Then, nine pigs fitted with T-shape cannulas at duodenal level and a jugular venous catheter were fed with the DHA-enriched egg products, and duodenal effluents and plasma were collected throughout the postprandial period. Results highlighted an undeniable effect of the food matrix on digestion parameters and DHA bioavailability. The transit of DHA and protein through the duodenum was faster after the ingestion of the mousse than after the ingestion of the omelet and hard-boiled egg. While most of the DHA and protein ingested under the form of mousse had already passed through the duodenum 4.5 h after its ingestion, significantly higher quantities were still present in the case of the omelet and hard-boiled egg. In terms of bioavailability, the omelet was the most efficient vector for delivering DHA into systemic circulation. It supplied 56% and 120% more DHA than the hard-boiled egg and the mousse, respectively.

State of the Art in Exocrine Pancreatic Insufficiency.

Exocrine pancreatic insufficiency (EPI) is defined as the maldigestion of foods due to inadequate pancreatic secretion, which can be caused by alterations in its stimulation, production, transport, or interaction with nutrients at duodenal level. The most frequent causes are chronic pancreatitis in adults and cystic fibrosis in children. The prevalence of EPI is high, varying according to its etiology, but it is considered to be underdiagnosed and undertreated. Its importance lies in the quality of life impairment that results from the malabsorption and malnutrition and in the increased morbidity and mortality, being associated with osteoporosis and cardiovascular events. The diagnosis is based on a set of symptoms, indicators of malnutrition, and an indirect non-invasive test in at-risk patients. The treatment of choice combines non-restrictive dietary measures with pancreatic enzyme replacement therapy to correct the associated symptoms and improve the nutritional status of patients. Non-responders require the adjustment of pancreatic enzyme therapy, the association of proton pump inhibitors, and/or the evaluation of alternative diagnoses such as bacterial overgrowth. This review offers an in-depth overview of EPI in order to support the proper management of this entity based on updated and integrated knowledge of its etiopathogenesis, prevalence, diagnosis, and treatment.

Solitary plasmacytoma extramedullary to duodenal level: an unusual case of intestinal occlusion

Plasma cell neoplasms represent only 1-2% of hematological malignancies and intestinal plasmocytoma represents only 3%. Extramedullary plasmocytomas most commonly are located in upper airway and oral cavity; the gastrointestinal plasmocytoma only represents 12%, the most frequent being the gastric one. We present a brief report about an extramedullary solitary plasmocytoma at the intestinal level (duodenum).

Study on Mesenchymal Artery Syndrome and Its Related Anatomy by MDCTA

Objective: To study the effect of MDCTA on the angle and distance of mesenteric artery and abdominal aorta in normal and superior mesenteric artery syndrome and its effect on duodenal level. Materials and Methods: Using MDCTA, retrospective observation of 108 cases of normal and 17 cases of superior mesenteric artery syndrome in patients with superior mesenteric artery and abdominal aortic angle and duodenal level mesenteric artery and abdominal aortic space, and compared. Results: All MDCTA of patients with superior mesenteric artery syndrome showed 'clamp pressure' of the superior mesenteric artery and abdominal aorta in the duodenal segment, causing duodenal obstruction. Among the 108 normal subjects, the angle between the superior mesenteric artery and the abdominal aorta was 46.3 ° ± 16.5 ° and 14.3 ° ± 5.6 ° in the superior mesenteric artery syndrome. The normal level of the duodenum was superior to the superior mesenteric artery Arterial distance of 14.7 ± 4.4mm, superior mesenteric artery syndrome in patients with 4.5 ± 0.8mm, the two groups of data have significant statistical differences. Conclusion: MDCTA can show the duodenal obstruction caused by the mesenteric artery and the abdominal aorta of the superior mesenteric artery syndrome, and can accurately show the angle between the superior mesenteric artery and the abdominal aorta the reduction of distance, the diagnosis of superior mesenteric artery syndrome has important clinical value.

Postweaning development of porcine small intestinal morphology and epithelial cell proliferation1

Histomorphometry and cell proliferation are markers of intestinal development, which we investigated in pigs from weaning to slaughter at 5 different small intestinal sites. Furthermore, the impact of enteral deoxynivalenol (DON) exposure on intestinal morphology and proliferation was studied. Postweaning pigs of 4 categories (1, 4, 8, and 12 wk after weaning) were slaughtered (4–6 pigs/category) and intestinal wall was collected from the duodenum, proximal jejunum, mid jejunum, and proximal and terminal ileum. Villus height and crypt depths were measured on histological specimens, and cell proliferation was determined by immunohistochemistry (5′-bromo-2′-deoxyuridine–positive or phosphohistone H3–positive cells) in the crypt area. All pigs were fed either a control diet or a DON-contaminated diet (approximately 3 mg/kg feed), and data were analyzed for the effect of gut axis, age, and diet. Villus height was only marginally affected by intestinal site, age, or diet, but crypt depth and cell proliferation showed a distinct pattern along the small intestinal axis. In pigs, irrespective of age or diet, the duodenum exhibited the deepest crypts (P < 0.05) but the lowest count of proliferating cell, albeit the latter was not always statistically significant. Moreover, there was a strong age effect on crypt depth at the duodenal and upper jejunal level but not in the lower intestinal sections: crypt depth increased dramatically (P < 0.01) between 1 (294 μm), 4 (505 μm), and 8 wk after weaning (508 μm). There was no difference between the 4-wk-after-weaning animals and older animals. We could not confirm a positive relationship between crypt depth and proliferating cell count. The presence of dietary DON did not significantly modify the development of the small intestine with respect to villus height, crypt depth, or epithelial cell proliferation.

Robotic radiosurgery in pancreatic cancer: A systematic review.

To present a systematic review of techniques and clinical results. A systematic review of published literature was performed. Only studies reporting patient outcome after radiosurgery (single fraction) delivered with robotic devices [i.e., robotic radiosurgery (RRS)] have been analyzed. A total of 96 patients from 5 studies were included. The studies are characterized by small series and different methods in terms of dose, target definition, combination with chemotherapy and/or standard fractionated radiotherapy and evaluation modalities. Preliminary results are positive in terms of tumor response (ORR = 56%) and local control of the tumor (crude rate of local progressions: 19.5%). Results for median overall survival (11.4 mo) seem comparable with the ones of prolonged chemoradiation (range: 8.6-13.0 mo). However, gastrointestinal toxicity seems to be the main limitation of RRS, especially at the duodenal level. RRS allows for local treatment in a shortened time (1 fraction) compared to traditional treatments (about 1 mo), providing the possibility for an easy integration with systemic therapies. Preliminary results did not show any outcome differences compared to standard chemoradiation. Thus, further efforts to reduce gastrointestinal toxicity are strongly needed.

English

Introduction Stereotactic body radiotherapy in the treatment of pancreatic carcinoma is a recent technique. The aim of this analysis is to present a summary of techniques and clinical results. Material and Methods Stereotactic body radiotherapy allows to perform a local treatment of the tumour in shortened time (1–5 days) compared with traditional treatments (about 1 month) but requires complex planning and delivery techniques with specific accessories for imageguided radiotherapy. The studies published to date are characterised by small series and very different methods in terms of dose, fractionation, techniques and evaluation modalities. Results The preliminary published results are positive in terms of tumour response (ORR: 50%) and local control of the tumour (crude rate: 80%). However, gastrointestinal toxicity seems to be the main limitation of stereotactic body radiotherapy, especially at the duodenal level. Conclusion If stereotactic body radiotherapy of pancreatic carcinoma will be standardised and optimised, reducing the risk of bowel toxicity, in the future it may have an increasing role in the field of integrated treatments of this tumour. Introduction The prognosis of pancreatic cancer pancreas is very unfavourable. Even in patients with non-metastatic disease at diagnosis, recurrences after primary therapy are very common both as a local relapse/progression and as distant metastases. Local recurrence rate, even of patients operated on, reached percentages of 70%–80%1,2. In addition, local disease progression produces severe symptoms (pain, biliary and/or intestinal obstruction, malnutrition) capable of significantly worsening the patients’ quality of life. Radiotherapy (RT) was used to promote local control of the disease. RT, usually associated with concurrent and adjuvant chemotherapy, is potentially useful to improve the resection rate3 and control symptoms in locally advanced carcinomas4 and to reduce the risk of recurrence in resected patients5. The main limitation of RT is the presence of radiosensitive organs in the upper abdomen in close proximity with the pancreas. In fact, due to these anatomic relationships, RT can produce severe side effects especially at the level of the duodenum. Therefore, a strong interest in the use of innovative precision RT techniques has developed, with the aim to administer effective doses * Corresponding author Email: gmacchia@rm.unicatt.it 1 Department of Radiation Oncology, Fondazione Giovanni Paolo II, Campobasso, Italy 2 Department of Medical Phisics, Fondazione Giovanni Paolo II, Campobasso, Italy 3 Department of Radiation Oncology, Ospedale San Francesco, Nuoro, Italy 4 Department of Radiation Oncology, Campus Biomedico University, Roma, Italy 5 Department of Radiation Oncology, Ospedale San Filippo Neri, Roma, Italy 6 Department of Radiation Oncology, Universita Cattolica del Sacro Cuore, Roma, Italy 7 Department of Medical Phisics, Universita Cattolica del Sacro Cuore, Roma, Italy 8 Department of General Oncology, Fondazione Giovanni Paolo II, Campobasso, Italy BODY

Human IgE binding and in vitro digestion of S-OVA

S-OVA, a more thermostable form of ovalbumin (OVA), was formed from native OVA or egg white in vitro, by heating at high pH, and by storage at low temperatures. S-OVA showed a much lower reactivity against IgE than OVA, although this difference in IgE binding was minimized after simulated gastro intestinal digestion, despite S-OVA was more resistant to proteolysis, particularly to pepsin, than its native form. It is, therefore, likely that the transformation of OVA to S-OVA does not affect its ability to sensitise or trigger allergic reactions at the duodenal level. These results are discussed in the light of the described conformational changes reported to occur in the transition between OVA and S-OVA.

Parallelism between central and enteric nervous system damage in experimental parkinsonism

Parkinson’s disease (PD) is a neurodegenerative condition which affects dopaminergic neurons of the substantia nigra (SN), leading to a movement disorder. Non motor alterations occur in several viscera, in particular the gastrointestinal tract. In 9-week old C57BL mice we examined the effects of the parkinsonism-inducing neurotoxin 1-methyl, 4-phenyl, 1,2,3,6,-tetrahydropyridine (MPTP, administered either acutely or chronically) in SN and striatum, as well as in duodenum. Motor tests (open field and PaGE) were performed. One week after treatment with MPTP (acute: 20 mg/KgX3, 2h apart or chonic: 5 mg/kg x2/die, for 3 weeks), histological investigations, immunohistochemistry and immunoblotting for tyrosine hydroxylase (TH), and α-synuclein (α-syn) were carried out. Immunocytochemical investigations were analyzed under electron microscopy. Motor tests showed a failure of the PaGE test in all MPTP-treated animals, whereas no difference was found in open field test in comparison with controls. Analysis of histological sections showed some alterations consisting of slight atrophy of duodenal mucosa and glandular disarrangement only after chronic treatment. Under electron microscopy the brush border appeared discontinuous. In all MPTP-administered mice, TH immunopositivity was reduced in SN and striatum, confirming its central dopaminergic neurotoxicity. At duodenal level, TH immunostaining was lost following all MPTP treatments with a slight variation in chronic compared with acute administrations. This was confirmed by semiquantitative immunoblotting. Moreover, α-syn immunostaining was enhanced by MPTP treatment but this was way more evident following chronic administration both at central and peripheral level. Following chronic treatment α-Syn immunopositive structures were investigated under electron microscopy. Our study shows that chronic more than acute administration of MPTP induces alterations at duodenal level reminiscent of dopaminergic damage in SN and striatum. Moreover, this experimental model of parkinsonism features gastrointestinal dysfunction observed in PD patients. These findings lend substance to the concept of the enteric nervous system as a double brain which recapitulates and is an ancestry of the central nervous system.

Evaluating the efficacy of cinnamaldehyde and Echinacea purpurea plant extract in broilers against Eimeria acervulina

Coccidiostats could be phased out as feed additives before 1 January 2013 for public health and food safety reasons, and, as a replacement, bioactive compounds found in plants are currently being investigated since they are more likely to be found acceptable by consumers. The aim of our study was to evaluate the effect of cinnamaldehyde (CIN) and Echinacea purpurea plant extract (EP) as additives by analyzing the performance traits, oocyst excretion and intestinal lesions following experimental infection with Eimeria acervulina. A total of 72 Ross male broilers were raised from 1 to 35d and randomly assigned to four dietary treatments: control, without additives (C); 150mgkg−1 cinnamaldehyde (CIN); 1000mgkg−1E. purpurea plant extract (EP); 150mgkg−1 cinnamaldehyde plus 1000mgkg−1E. purpurea plant extract (CIN+EP). At 25d, 12 chickens per treatment were orally infected with E. acervulina. Coccidia infestation led to lower performance but with no significant differences between the infected groups. Oocyst output reached its peak from 6 to 9d post-infection in all treatments. At duodenal level, gross lesion scores were lower for cinnamaldehyde diets (P<0.05). A similar trend was observed in the microscopic lesion scores, with a non-significant reduction as a result of cinnamaldehyde addition (P>0.05). Scoring methods for macro- and microscopic lesions showed a positive linear relationship (G=+0.70). Further studies are necessary to assess the possible anticoccidian action of the cinnamaldehyde and its value as an alternative or adjunct in therapeutic or prophylactic strategies.

Apparent ruminal synthesis and intestinal disappearance of vitamin B12 and its analogs in dairy cows

The aim of the project was to calculate the apparent synthesis or destruction of cobalamin (vitamin B12) and its analogs in the rumen as well as their apparent intestinal disappearance in dairy cows. Four lactating cows were fed a diet supplemented with cobalt alone (0.76mg/kg of DM; control) or with cobalt and vitamin B12 (cyanocobalamin, 500mg/d; treated). In addition to cobalamin, the only biologically active molecule for the cow, 7 analogs were identified in duodenal and ileal digesta: cobinamide, which lacks the base, ribose, and phosphate groups; and 6 other molecules in which the base, 5,6-dimethylbenzimidazole, is replaced by cresol, 2-CH3-adenine, adenine, 2-CH3-S-adenine, or 5-OH-benzimidazole, or an unidentified cobamine. Small amounts of cobalamin and cobinamide were detected in the total mixed ration, but apparent synthesis of all forms took place in rumen. During the control period, cobalamin represented 38% of the total amounts of corrinoids produced in rumen. Approximately 11% of the average daily intake of cobalt was used for apparent ruminal synthesis of corrinoids, of which only 4% was incorporated into cobalamin. Only 20% of the supplement of cyanocobalamin was recovered at the duodenal level; cobinamide appeared to be the major product of degradation of supplementary cyanocobalamin in the rumen. During the control and treatment periods, there was an apparent intestinal disappearance of cobalamin and 5-OH-benzimidazole cobamide only; only the apparent intestinal disappearance of cobalamin differed between the 2 periods. Although cobalamin was not the major form synthesized by ruminal microflora and, even if supplementary cyanocobalamin was extensively destroyed by ruminal microflora, based on calculations of apparent intestinal disappearance, cobalamin seems to be the major form absorbed in the small intestine.

Effect of unsaturated fatty acid supplementation on performance and milk fatty acid profile in dairy cows fed a high fibre diet

The influence of unsaturated fatty acid (UFA) supplement on productive performance, physiochemical properties and fatty acid (FA) profile of milk, was investigated in lactating dairy cows fed with high fibre diets. According to a cross-over design, twelve cows were assigned to two experimental settings characterized by different FA profiles. Cows received a high fibre diet (~42% NDF on DM basis) supplemented with soybean based mixtures with these FA compositions: 92.0% of saturated FA (SFA), 2.8% of monounsaturated FA (MUFA) and 5.2% of polyunsaturated FA (PUFA) in the control diet (C-diet); 19.1% of SFA, 20.9% of MUFA and 60.0% of PUFA in the experimental diet (E-diet).The E-diet did not affect dry matter intake nor milk yield. Milk composition and coagulation traits resulted similar between treatments, except for the lactose level, which was lower in the E-diet (5.0 vs 4.8%; P<0.05) and the freezing point (-0.546 vs -0.535 °C; P<0.05). As respects the milk FA profile, the E-diet significantly increased the percentage of UFA because of their greater amount in the ration; however the “transfer” of UFA in milk was limited by the high level of FA biohydrogenation (BH) at the ruminal level.UFA showed low values of carry over in milk (67.5 vs 39.7%; P<0.001) due to the saturation process; on the contrary SFA had a threefold increment (124 vs 323%; P<0.001), mostly due to a peak in the production of stearic acid. In this study, the percentage of CLA in milk (0.50 vs 0.62%; P<0.05) was quite low for both diets, if compared with other studies, and this was probably due to a low vaccenic acid supply at duodenal level.

Effects of processing of wheat or oats starch on physical pellet quality and nutritional value for broilers

Two experiments were conducted to investigate the influence of cereal starch exposed to various processing techniques on physical pellet quality and nutritional value of the diets fed to broiler chickens. In experiment 1, diets with equal amounts of oat hulls, rapeseeds and fish meal were cold-pelleted or steam-conditioned and pelleted with or without inclusion of 200 g pure wheat starch/kg. Durability of the pellets was reduced ( p<0.05) for the starch-containing diets compared to non-starch diets under both processing conditions. Despite a significant improvement ( p<0.05) in pellet quality within starch containing-diets as a consequence of gelatinised starch addition, pellet durability was lower ( p<0.05) for gelatinised starch-containing diets compared to non-starch diets. In experiment 2, wheat and de-hulled oat-based diets were cold-pelleted, steam-pelleted or extruded before being fed to broiler chickens. The extent of starch gelatinisation was higher for oat diets than for wheat diets under all processing conditions. Feed/gain was lower ( p<0.05) and AME n higher ( p<0.05) for oat versus wheat diets. The increase in AME n was also reflected in starch digestibility which was significantly higher for oats compared to wheat diets in all segments of the gastrointestinal tract. As a consequence of increased gelatinisation a significant improvement ( p<0.05) in starch digestibility was observed for extruded wheat diets compared with either cold- or steam-pelleted wheat diets. An improved ( p<0.05) starch digestibility due to extrusion processing was only observed at a duodenal level for oat diets.

HFE Modulates Transferrin Receptor 2 Levels in Hepatoma Cells via Interactions That Differ from Transferrin Receptor 1-HFE Interactions

Mutations in the transmembrane glycoproteins transferrin receptor 2 (TfR2) and HFE are associated with hereditary hemochromatosis. Interactions between HFE and transferrin receptor 1 (TfR1) have been mapped to the alpha1- and alpha2-helices in HFE and to the helical domain of TfR1. Recently, TfR2 was also reported to interact with HFE in transfected mammalian cells. To test whether similar HFE residues are important for both TfR1 and TfR2 binding, a mutant form of HFE (W81AHFE) that has an approximately 5,000-fold lower affinity for TfR1 than HFE was employed. As expected, W81AHFE does not interact with TfR1. However, we found that the same mutation in HFE does not affect the TfR2/HFE interaction. This finding indicates that the TfR2/HFE and TfR1/HFE interactions are distinct. We further observed that, unlike TfR1/HFE, Tf does not compete with HFE for binding to TfR2 and that binding is independent of pH (pH 6-7.5). TfR2-TfR1 and HFE-HLA-B7 chimeras were generated to map the domains of the TfR2/HFE interaction. TfR1 and HLA-B7 were chosen because of their similar overall structures with TfR2 and HFE, respectively. We mapped the interacting domains to the putative stalk and protease-like domains of TfR2 located between residues 104 and 250 and to the alpha3 domain of HFE, both of which differ from the TfR1/HFE interacting domains. Furthermore, we found that HFE increases TfR2 levels in hepatic cells independent of holo-Tf.

Ileal exposure to pig pancreatic juice and bile inhibit exocrine pancreatic secretion in pigs

The mechanisms involved in the down regulation of the exocrine pancreas are still not fully elucidated. The purpose of the present study was to examine the effect of duodenal and ileal exposure to pancreatic enzymes and bile on pancreatic secretion. Experiments were performed with pigs fitted with pancreatic duct, ileal and jugular vein catheters, and duodenal T-shaped cannula. A negative feedback regulation of pancreatic secretion was found for both duodenal and ileal delivery of pancreatic juice. Pancreatic secretion was unaffected by duodenal delivery of bile and bile salts, while ileal delivery of bile and bile salts lowered it. On the other hand, pancreatic secretion was increased by duodenal loading of commercial non- or activated pancreatic enzyme preparations, thus probably recognised as dietary protein. Plasma cholecystokinin (CCK) level was lowered only by duodenal delivery of pancreatic juice. In conclusion, the results prove the existence of negative feedback mechanism regulating pancreatic secretion dependent on the presence of pure pancreatic juice or bile at the ileal level. The mechanism at the duodenal level is exclusively sensitive to pure pancreatic juice. (c) 2007 Elsevier B.V All rights reserved. (Less)

CCK‐B receptor antagonist YF476 inhibits pancreatic enzyme secretion at a duodenal level in pigs

Background: To evaluate the mechanisms by which cholecystokinin (CCK) regulates the exocrine pancreas, the role and location of CCK receptors in the pig were investigated using the CCK‐B receptor antagonist YF476 and different administration routes of CCK. Methods: In 11 anaesthetized pigs, catheters were surgically implanted in the pancreatic duct for juice collection, and in the gastric arteries and jugular vein, so that infusions of CCK‐33 could be directed to the duodenal/gastric, duodenal/pancreatic or general circulations, respectively. Experiments were performed under control conditions, and after pretreatment by gavage feeding with YF476, using either a single, low dose of 0.3 μmol kg−1, which would block the CCK‐B receptors, or a 1000 times higher dose (300 μmol kg−1), which would also block the CCK‐A receptors. Results: The increase in the pancreatic output of protein and the enzymes trypsin and amylase observed after the infusion of CCK‐33 at 13 pmol kg−1to the duodenum/stomach or duodenum/pancreas was inhibited by pretreatment with YF476 at both dosages. In contrast, the increase in protein and enzyme output after the infusion of a supraphysiological dose of CCK‐33 (130 pmol kg−1) to the general circulation was not affected by pretreatment with low dosage YF476, whereas high dosage YF476 completely inhibited the stimulated secretion. Conclusions: These data indicate that CCK‐33 given locally to the duodenum in doses raising CCK to physiological plasma levels stimulates the pancreatic enzyme secretion via duodenal CCK‐B receptors. Supra‐physiological doses of CCK‐33 to the general circulation appeared to affect the pancreatic enzyme secretion via CCK‐A receptors located elsewhere than in the pancreatic and duodenal tissue.

Apparent Precaecal Digestibility of Nutrients and Level of Endogenous Nitrogen in Digesta of the Small Intestine of Growing Pigs as Affected by Various Digesta Viscosities

Sixteen male growing pigs of about 24kg BW were fitted with both a duodenal re-entrant and a post-valve T-shaped cannula inserted in the caecum. The animals were divided into four groups. Each group received one of the following diets: corn starch-soybean protein isolate-based diet without (diet C) and with carboxymethylcellulose (diet CMC) or a rye-wheat-based diet without (diet RW) and with xylanase addition (diet RWX). The diets provided similar levels of apparent precaecal digestible crude protein (CP), lysine, methionine+cystine, threonine and tryptophan. Additionally, [15N]-yeast was given with the diets during the first 10 days of the experiment. For estimation of digesta viscosity, N-flow of dietary and endogenous origin, apparent precaecal digestibilities of dry matter (DM), CP, amino acids and non starch polysaccharides (NSP) (only in pigs fed diets RW and RWX), ileal and duodenal digesta were quantitatively collected on day 16 and 17, respectively. The endogenous N-proportion was measured by the ratio of 15N enrichment in the digesta and urine. The duodenal and ileal digesta supernatant viscosity increased as carboxymethylcellulose was included into the diet. Xylanase addition to the rye-wheat based diet reduced the viscosity in the ileal digesta. There were no differences in precaecal digestibilities of DM, CP and amino acids between diet C and CMC. The precaecal digestibilities of DM and soluble and insoluble NSP increased from 69.5% to 73.9%, from 1.3% to 47.9% and from 17.0% to 35.4%, respectively, as xylanase was added to the rye-wheat-based diet. The apparent precaecal digestibility of most essential amino acids increased by 2 to 5 percent units. The amounts of endogenous N at the duodenal level were estimated to be 158, 233, 313 and 276mg per 12h per kg0.75 BW of pigs fed diets C, CMC, RW and RWX, respectively. The corresponding values at the ileal level were 95, 107, 164 and 150mg per 12h per kg0.75 BW. For endogenous N amounts, significant differences were observed between diets C and CMC (duodenum) and also between semi-purified and cereal-based diets (duodenum and ileum). Methodological aspects for the estimation of endogenous N using the isotope dilution technique are discussed. Obviously, the digesta viscosity per se does not affect the nutrient absorption and endogenous N flow within the small intestine of pigs. Other properties of complex dietary fibre, digesta passage rate or bacterial activity probably contribute to the observed changes.