Anti-Incretin Gut Features Induced by Feed Supplementation with Alpha-Amylase: Studies on EPI Pigs.

The acini-islet-acinar (AIA) axis concept justifies the anatomical placement of the Langerhans islets within the exocrine pancreatic parenchyma and explains the existence of the pancreas as a single organ. Amylase has been suggested to play a key role as an anti-incretin factor. Oral glucose tolerance tests (OGTT) were performed on 18 piglets in both a healthy (prior to pancreatic duct ligation (PDL) surgery, study Day 10) and an exocrine pancreatic insufficient (EPI) state (30 days after PDL, study Day 48)). Amylase (4000 units/feeding) or Creon® (100,000 units/feeding) was administered to pigs with the morning and evening meals, according to study design randomization, for 37 days following the first OGTT. Blood glucose levels, as well as plasma levels of insulin, GLP-1, and GIP, were measured, and the HOMA-IR index was calculated. EPI status did not affect the area under the curve (AUC) of insulin release, fasting insulin levels, or the HOMA-IR index, while amylase supplementation led to a significant (p < 0.05) decrease in the above-mentioned parameters. At the same time, EPI led to a significant (p < 0.05) increase in GLP-1 levels, and neither amylase nor Creon® supplementation had any effects on this EPI-related increase. Fasting plasma levels of GIP were not affected by EPI; however, the GIP response in EPI and Amylase-treated EPI animals was significantly lower (p < 0.05) when compared to that of the intact, healthy pigs. Orally administered amylase induces gut anti-incretin action, normalizing glucose homeostasis and reducing HOMA-IR as a long-term outcome, thus lowering the risk of diabetes type II development. Amylase has long-lasting anti-incretin effects, and one could consider the existence of a long-lasting gut memory for amylase, which decreases hyperinsulinemia and hyperglycemia for up to 16 h after the last exposure of the gut to amylase.

Maternal HMB treatment affects bone and hyaline cartilage development in their weaned piglets via the leptin/osteoprotegerin system.

It has been demonstrated in animal studies that prenatal administration of ß-hydroxy-ß-methylbutyrate (HMB, metabolite of leucine) influences general growth and mechanical endurance of long bones in newborn offspring in sex-dependent manner. The present experiment was conducted to evaluate the effect of HMB treatment of pregnant sows on bone development in offspring at weaning. From 70th day until the 90th day of gestation, sows received either a basal diet (n = 12) or the same diet supplemented with HMB (n = 12) at the dose of 0.2 g/kg of body weight/day. Femora obtained from six males and females in each group weaned at the age of 35 days were examined. Maternal HMB treatment significantly enhanced body weight and changed bone morphology increasing femur mechanical strength in both sexes. Maternal HMB supplementation also elevated bone micro- and macroelement concentrations and enhanced content of proteoglycans in articular cartilage. Based on the obtained results, it can be concluded that maternal HMB supplementation in the mid-gestation period significantly accelerated bone development in both sexes by upregulation of a multifactorial system including leptin and osteoprotegerin. However, the sex (irrespective of the HMB treatment) was the factor which influenced the collagen structure in cartilages and trabecular bone, as demonstrated both by the Picrosirius red staining and performed analysis of thermal stability of collagenous tissues. The structural differences in collagen between males and females were presumably related to a different collagen maturity. No studies conducted so far provided a detailed morphological analysis of bone, articular cartilage, growth plate and the activities of the somatotropic and pituitary-gonadal axes, as well as leptin/osteoprotegerin system in weaned offspring prenatally treated with HMB. This study showed also the relationship between the maternal HMB treatment and bone osteometric and mechanical traits, hormones, and growth and bone turnover markers such as leptin, osteoprotegerin and insulin-like growth factor-1.

Decreased insulin secretion and glucose clearance in exocrine pancreas-insufficient pigs.

The effect of exocrine pancreatic function on the glucose-mediated insulin response and glucose utilization were studied in an exocrine pancreas-insufficient (EPI) pig model. Five 10-week-old EPI pigs after pancreatic duct ligation and 6 age-matched, non-operated control pigs were used in the study. Blood glucose, plasma insulin and C-peptide concentrations were monitored during meal (MGTT), oral (OGTT) and intravenous (IVGTT) glucose tolerance tests. Upon post-mortem examination, the pancreatic remnants of the EPI pigs showed acinar fibrotic atrophy but normal islets and ß-cell morphology. The EPI pigs displayed increased fasting glucose concentrations compared with control animals (6.4 ± 0.4 versus 4.8 ± 0.1 mmol l(-1) , P < 0.0001) but unchanged insulin concentrations (2.4 ± 0.6 versus 2.1 ± 0.2 pmol l(-1) ). During the OGTT and IVGTT, the EPI pigs showed slower, impaired glucose utilization, with the disruption of a well-timed insulin response. Plasma C-peptide concentrations confirmed the delayed insulin response during the IVGTT in EPI pigs. Oral pancreatic enzyme supplementation (PES) of EPI pigs improved glucose clearance during IVGTT [AUC(glucose) 1295 ± 70 mmol l(-1) × (120 min) in EPI versus 1044 ± 32 mmol l(-1) × (120 min) in EPI + PES, P < 0.0001] without reinforcing the release of insulin [AUC(C-peptide) 14.4 ± 3.8 nmol l(-1) × (120 min) in EPI versus 6.4 ± 1.3 nmol l(-1) × (120 min) in EPI + PES, P < 0.002]. The results suggest the existence of an acino-insular axis regulatory communication. The presence of pancreatic enzymes in the gut facilitates glucose utilization in an insulin-independent manner, indicating the existence of a gut-derived pancreatic enzyme-dependent mechanism involved in peripheral glucose utilization.

Dietary alpha-ketoglutarate increases cold tolerance in Drosophila melanogaster and enhances protein pool and antioxidant defense in sex-specific manner.

Alpha-ketoglutarate (AKG) is an important intermediate in Krebs cycle which bridges the metabolism of amino acids and carbohydrates. Its effects as a dietary supplement on cold tolerance were studied in Drosophila melanogaster Canton S. Two-day-old adult flies fed at larval and adult stages with AKG at moderate concentrations (5-10mM) recovered faster from chill coma (0°C for 15min or 3h) than control ones. The beneficial effect of AKG on chill coma recovery was not found at its higher concentrations, which suggests hormetic like action of this keto acid. Time of 50% observed mortality after 2h recovery from continuous cold exposure (-1°C for 3-31h) (LTi50) was higher for flies reared on 10mM AKG compared with control ones, showing that the diet with AKG enhanced insect cold tolerance. In parallel with enhancement of cold tolerance, dietary AKG improved fly locomotor activity. Metabolic effects of AKG differed partly in males and females. In males fed on AKG, there were no differences in total protein and free amino acid levels, but the total antioxidant capacity, catalase activity and low molecular mass thiol content were higher than in control animals. In females, dietary AKG promoted higher total antioxidant capacity and higher levels of proteins, total amino acids, proline and low molecular mass thiols. The levels of lipid peroxides were lower in both fly sexes reared on AKG as compared with control ones. We conclude that both enhancement of antioxidant system capacity and synthesis of amino acids can be important for AKG-promoted cold tolerance in D. melanogaster. The involvement of AKG in metabolic pathways of Drosophila males and females is discussed.

A piglet with surgically induced exocrine pancreatic insufficiency as an animal model of newborns to study fat digestion.

The maldigestion and malabsorption of fat in infants fed milk formula results due to the minimal production of pancreatic lipase. Thus, to investigate lipid digestion and absorption and mimic the situation in newborns, a young porcine exocrine pancreatic insufficient (EPI) model was adapted and validated in the present study. A total of thirteen EPI pigs, aged 8 weeks old, were randomised into three groups and fed either a milk-based formula or a milk-based formula supplemented with either bacterial or fungal lipase. Digestion and absorption of fat was directly correlated with the addition of lipases as demonstrated by a 30% increase in the coefficient of fat absorption. In comparison to the control group, a 40 and 25% reduction in total fat content and 26 and 45% reduction in n-3 and n-6 fatty acid (FA) content in the stool was observed for lipases 1 and 2, respectively. Improved fat absorption was reflected in the blood levels of lipid parameters. During the experiment, only a very slight gain in body weight was observed in EPI piglets, which can be explained by the absence of pancreatic protease and amylase in the gastrointestinal tract. This is similar to newborn babies that have reduced physiological function of exocrine pancreas. In conclusion, we postulate that the EPI pig model fed with infant formula mimics the growth and lipid digestion and absorption in human neonates and can be used to elucidate further importance of fat and FA in the development and growth of newborns, as well as for testing novel formula compositions.

A review: Pancreatic enzymes in the treatment of chronic pancreatic insufficiency in companion animals.

The purpose of this review was to analyze the scientific literature on exocrine pancreatic insufficiency (EPI) in dogs and cats and our own research on porcine model to compare animal- and microbial-derived enzymes in the treatment of animals with this disease. Clinical signs of EPI occur when more than 85% of the pancreatic parenchyma is non-functional. EPI can be a consequence of various diseases. The insufficient activity or deficiency of pancreatic enzymes leads to impaired digestion and absorption, and consequently, to malnutrition. The primary treatment for enzyme insufficiency is pancreatic enzyme replacement therapy (PERT). PERT in animals with EPI is a lifetime therapy. Most commercially available products are of animal origin (processed pancreata obtained from a slaughter house) and contain lipases, alpha-amylase, and proteases. Enzymes of microbial and plant origin seem to be a promising alternative to animal-derived enzymes, but to date there are no registered preparations containing all enzymes simultaneously for use in clinical practice to treat EPI. Results from some previous studies have highlighted the "extra-digestive" functions of pancreatic enzymes, as well as the actions of pancreatic-like microbial enzymes. For example, trypsin activates protease-activated receptor and provokes maturation of enterocytes and enterostatin inhibits fat absorption. It has been postulated that intrapancreatic amylase is the main component of the acini-islet-acinar axis-the reflex which down regulates insulin release, while gut and blood amylase exhibit anti-incretin actions "per se." Additionally, high but still physiological blood amylase activity coincide with physiological glucose homeostasis and a lack of obesity.

Amylase intrapancreatic infusion delays insulin release during an intravenous glucose tolerance test, proof of acini-islet-acinar interactions.

BACKGROUND: The possible existence of an acini-islet-acinar (AIA) reflex, involving mutual amylase and insulin interactions, was investigated in the current acute experiment on pigs. AIM: To confirm the existence of an AIA reflex and justify the placement of the exocrine and endocrine pancreatic components within the same organ. METHODS: The study was performed on six pigs under general anesthesia. An intravenous glucose tolerance test was performed, with a bolus infusion of 50% glucose to the jugular vein, while amylase (5000 U/kg) or vehicle intrapancreatic infusions were administered via the pancreaticoduodenalis cranialis artery during 30 min with a 1 mL/min flow rate. RESULTS: The amylase infusion to pancreatic arterial circulation inhibited and delayed the insulin release peak which is usually associated with the highest value of blood glucose and is typically observed at 15 min after glucose infusion, for > 1 h. The intrapancreatic infusion of the vehicle (saline) did not have any effect on the time frame of insulin release. Infusion of 1% bovine serum albumin changed the insulin release curve dramatically and prolonged the high range of insulin secretion, far beyond the glucose peak. CONCLUSION: Intrapancreatic arterial infusion of amylase interrupted the integrated glucose-insulin interactions. This confirms an AIA reflex and justifies placement of the exocrine and endocrine pancreatic components within the same organ.

The effect of dietary administration of 2-oxoglutaric acid on the cartilage and bone of growing rats.

2-Oxoglutaric acid (2-Ox), a precursor to hydroxyproline - the most abundant amino acid in bone collagen, exerts protective effects on bone development during different stages of organism development; however, little is known about the action of 2-Ox on cartilage. The aim of the present study was to elucidate the influence of dietary 2-Ox supplementation on the growth plate, articular cartilage and bone of growing rats. A total of twelve male Sprague-Dawley rats were used in the study. Half of the rats received 2-oxoglutarate at a dose of 0·75 g/kg body weight per d in their drinking-water. Body and organ weights were measured. Histomorphometric analyses of the cartilage and bone tissue of the femora and tibiae were conducted, as well as bone densitometry and peripheral quantitative computed tomography (pQCT). Rats receiving 2-Ox had an increased body mass (P<0·001) and absolute liver weight (P=0·031). Femoral length (P=0·045) and bone mineral density (P=0·014), overall thickness of growth plate (femur P=0·036 and tibia P=0·026) and the thickness of femoral articular cartilage (P<0·001) were also increased. 2-Ox administration had no effect on the mechanical properties or on any of the measured pQCT parameters for both bones analysed. There were also no significant differences in histomorphometric parameters of tibial articular cartilage and autofluorescence of femoral and tibial growth plate cartilage. Dietary supplementation with 2-Ox to growing rats exerts its effects mainly on cartilage tissue, having only a slight influence on bone. The effect of 2-Ox administration was selective, depending on the particular bone and type of cartilage analysed.

Hypothesis that alpha-amylase evokes regulatory mechanisms originating in the pancreas, gut and circulation, which govern glucose/insulin homeostasis.

The anti-incretin theory involving the abolishment of diabetes type (DT) II by some of methods used in bariatric surgery, first appeared during the early years of the XXI century and considers the existence of anti-incretin substances. However, to date no exogenous or endogenous anti-incretins have been found. Our concept of the acini-islet-acinar axis assumes that insulin intra-pancreatically stimulates alpha-amylase synthesis ("halo phenomenon") and in turn, alpha-amylase reciprocally inhibits insulin production, thus making alpha-amylase a candidate for being an anti-incretin. Additionally, gut as well as plasma alpha-amylase, of pancreatic and other origins, inhibits the appearance of dietary glucose in the blood, lowering the glucose peak after iv or oral glucose loading. This effect of alpha-amylase can be interpreted as an insulin down regulatory mechanism, possibly limiting the depletion of pancreatic beta cells and preventing their failure. Clinical observations agree with the above statements, where patients with high blood alpha-amylase concentrations are seldom obese and seldom develop DT2. Obese-DT2, as well as DT1 patients, usually develop exo-crine pancreatic insufficiency (EPI) and vice versa. Ultimately, DT2 patients develop DT1, when the pancreatic beta cells are exhausted and insulin production ceases. Studies on biliopancreatic diversion (BPD) and on BPD with duodenal switch, a type of bariatric surgery, as well as studies on EPI pigs, allow us to observe and investigate the above-mentioned phenomena of intra-pancreatic interactions.

Selective and Concentrative Enteropancreatic Recirculation of Antibiotics by Pigs.

Antibiotics that are efficacious for infectious pancreatitis are present in pancreatic exocrine secretion (PES) after intravenous administration and above minimal inhibitory concentrations. We measured concentrations of four antibiotics by tandem liquid chromatography-mass spectroscopy in plasma and PES after enteral administration to juvenile pigs with jugular catheters and re-entrant pancreatic-duodenal catheters. Nystatin, which is not absorbed by the intestine nor used for infectious pancreatitis (negative control), was not detected in plasma or PES. Concentrations of amoxicillin increased in plasma after administration (p = 0.035), but not in PES (p = 0.51). Metronidazole and enrofloxacin that are used for infectious pancreatitis increased in plasma after enteral administration and even more so in PES, with concentrations in PES averaging 3.1 (±0.5)- and 2.3 (±0.6)-fold higher than in plasma, respectively (p's < 0.001). The increase in enrofloxacin in PES relative to plasma was lower after intramuscular administration (1.8 ± 0.5; p = 0.001). The present results demonstrate the presence of a selective and concentrative enteropancreatic pathway of secretion for some antibiotics. Unlike the regulated secretion of bile, the constitutive secretion of PES and intestinal reabsorption may provide a continuous exposure of pancreas tissue and the small intestine to recirculated antibiotics and potentially other therapeutic molecules. There is a need to better understand the enteropancreatic recirculation of antibiotics and the associated mechanisms.

Validation of an omega-3 substrate challenge absorption test as an indicator of global fat lipolysis.

INTRODUCTION: The coefficient of fat absorption (CFA) quantifies fat that remains in stool after digestion and is not a direct measure of lipolysis. CFA has been used to assess treatment of pancreatic insufficiency but does not correlate with pancreatic enzyme replacement therapy dose. We explored use of an omega-3 substrate absorption challenge test as a sensitive test of lipolysis and absorption. METHODS: We studied a novel microbially-derived lipase (SNSP003) employing an established surgical model commonly used to study the uptake of macronutrients, the exocrine pancreatic insufficient pig. Pigs were fed a high-fat diet and given a standardized omega-3 substrate challenge to test the effect of lipolysis on its absorption. Blood was drawn at 0, 1, 2, 4, 6, 8, 12, and 24 hours following the substrate challenge and was analyzed for omega-3 and total fat levels (c14:c24). SNSP003 was also compard to porcine pancrelipase. RESULTS: The absorption of omega-3 fats was significantly increased following administration of 40, 80 and 120 mg SNSP003 lipase by 51% (p = 0.02), 89%, (p = 0.001) and 64% (p = 0.01), respectively, compared to that observed when no lipase was administered to the pigs, with Tmax at 4 hours. The two highest SNSP003 doses were compared to porcine pancrelipase and no significant differences were observed. Both doses increased plasma total fatty acids (141% for the 80 mg dose (p = 0.001) and 133% for the 120 mg dose (p = 0.006), compared to no lipase) and no significant differences were observed between the SNSP003 lipase doses and porcine pancrelipase. CONCLUSION: The omega-3 substrate absorption challenge test differentiates among different doses of a novel microbially-derived lipase and correlates with global fat lipolysis and absorption in exocrine pancreatic insufficient pigs. No significant differences were observed between the two highest novel lipase doses and porcine pancrelipase. Studies in humans should be designed to support the evidence presented here that suggests the omega-3 substrate absorption challenge test has advantages over the coefficient of fat absorption test to study lipase activity.

Anti-osteopenic effect of alpha-ketoglutarate sodium salt in ovariectomized rats.

The purpose of the study was to determine the effect of alpha-ketoglutarate sodium salt (AKG) treatment on the mineralization of the tibia in female rats during the development of osteopenia (Experiment-1) and in the condition of established osteopenia (Experiment-2). Thirty-two female rats were ovariectomized (OVX) to induce osteopenia and osteoporosis and another 32 female rats were sham-operated (SHO) and then randomly divided between the two experiments. In Experiment-1, the treatment with AKG started after a 7-day period of convalescence, whereas in Experiment-2 the rats were subjected to a 60-day period of osteopenia fixation, after which the actual experimental protocol commenced. AKG was administered in the experimental solution for drinking at a concentration of 1.0 mol/l and a placebo (PLC) was used as a control solution. After 60 days of experimental treatment the rats in both experiements were sacrificed, the body weight recorded, and blood serum and isolated tibia were stored for further analysis. The bones were analyzed using tomography and densitometry, and for estimation of mechanical properties the 3-point bending test was used. Serum concentrations of osteocalcin and collagen type I crosslinked C-telopeptide were measured. The anabolic effects of AKG on bone during osteopenia development in Experiment-1 not only stopped the degradation of bone tissue, but also stimulated its mineralization. The usage of AKG in animals with established osteopenia (Experiment-2) was not able to prevent bone atrophy, but markedly reduced its intensity. The stimulation of tibia mineralization after AKG treatment has been also argued in healthy SHO animals. The results obtained prove the effectiveness of AKG usage in the prophylaxis and therapy of osteopenia and osteoporosis, induced by bilateral gonadectomy. Additionally, the results clearly prove that treatment with AKG improves the mineralization of bone tissue in healthy animals.

Alpha-ketoglutarate (AKG) inhibits proliferation of colon adenocarcinoma cells in normoxic conditions.

BACKGROUND AND OBJECTIVE: Alpha-ketoglutarate (AKG), a key intermediate in Krebs cycle, is an important biological compound involved in the formation of amino acids, nitrogen transport, and oxidation reactions. AKG is already commercially available as a dietary supplement and its supplementation with glutamine, arginine, or ornithine alpha-ketoglutarate has been recently considered to improve anticancer immune functions. It is well documented that AKG treatment of Hep3B hepatoma cells in hypoxia induced HIF-alpha (hypoxia-inducible factor) degradation and reduced vascular endothelial growth factor (VEGF) synthesis. Moreover, AKG showed potent antitumor effects in murine tumor xenograft model, inhibiting tumor growth, angiogenesis, and VEGF gene expression. However, the mechanisms of its anticancer activity in normoxia have not been examined so far. RESULTS: Here, we report that in normoxia, AKG inhibited proliferation of colon adenocarcinoma cell lines: Caco-2, HT-29, and LS-180, representing different stages of colon carcinogenesis. Furthermore, AKG influenced the cell cycle, enhancing the expression of the inhibitors of cyclin-dependent kinases p21 Waf1/Cip1 and p27 Kip1. Moreover, expression of cyclin D1, required in G1/S transmission, was decreased, which accompanied with the significant increase in cell number in G1 phase. AKG affected also one the key cell cycle regulator, Rb, and reduced its activation status. CONCLUSION: In this study for the first time, the antiproliferative activity of AKG on colon adenocarcinoma Caco-2, HT-29, and LS-180 cells in normoxic conditions was revealed. Taking into consideration an anticancer activity both in hypoxic and normoxic conditions, AKG may be considered as a new potent chemopreventive agent.

Alpha-ketoglutarate, a key molecule involved in nitrogen circulation in both animals and plants, in the context of human gut microbiota and protein metabolism.

PURPOSE: Nitrogen (N2) is an indispensable metabolite required for the synthesis of protein. In animals, gut bacteria and, to a certain extent, even hepatocytes, are able to assimilate nitrogen from ammonium (NH4+), which is essentially derived from the amine group (-NH2) and which is at the same time a very toxic metabolite. Initially, NH4+ is coupled to alpha-ketoglutarate (AKG), a reaction which results in the appearance of glutamate (one amine group), and after that, in the appearance of glutamine - containing two amine groups. The surplus of NH4+ which is not utilized by AKG/glutamate/glutamine is eliminated as urea in the urine, via the urea cycle in hepatocytes. Plants bacteria also assimilate nitrogen from NH4+, by its fixation to ammonia (NH3)/NH4+. MATERIALS/METHODS: Previous studies have shown that AKG (also known as 2-oxo-glutaric acid or 2-oxopentanedioic acid), the primary metabolite of Rhizobium and gut bacteria, is essential for the assimilation of nitrogen. RESULTS: Symbiotic bacteria produce AKG, which together with glutamate dehydrogenase (GDH), 'generates' primarily amine groups from NH4+. The final product is glutamate - the first amino acid. Glutamate has the capacity to be converted to glutamine, through the action of glutamine synthetase, after the assimilation of the second nitrogen from NH4+. CONCLUSION: Glutamate/glutamine, derivatives of AKG metabolism, are capable of donating amine groups for the creation of other amino acids, following NH2 transamination to certain metabolites e.g., short chain fatty acids (SCFA).

Pre-digestion of the lipids in infant formula affects gut maturation of the preterm pig.

Preterm birth is associated with increased risk of complications, specifically with regards to the gastrointestinal tract. These complications mainly include the maldigestion and malabsorption of nutrients resulting from the immaturity of the small intestine. The current study investigated whether pre-digestion of fat in infant formula would affect the developmental remodeling of the structure of the small intestine mucous membrane. Three groups of premature piglets (corresponding to 30-32 week of human gestation) were used in the study: the first group, not subjected to any treatment and euthanized within 2 hours after caesarian delivery, was used as the control group (PT group), the second group, was fed an infant formula-IF (SPT group), and the third group was fed a lipase pre-hydrolyzed infant formula-hIF (PPT group). Feeding preterm piglets with an infant formula for 14 days stimulated intestinal maturation (in SPT and PPT groups). However, pre-digestion of the infant formula with lipase significantly increased proliferative activity and intensity of apoptosis in the small intestine epithelium, resulting in more rapid enterocyte turnover. The data obtained not only confirm that starting enteral feeding directly after birth stimulates developmental and structural changes in the small intestine, but also highlighted the importance of lipid digestion for enterocyte turnover and speeding up of intestinal maturation in preterm piglets. The latest is of high importance for the proper gut development of preterm children.

Dietary Alpha-Ketoglutarate Partially Abolishes Adverse Changes in the Small Intestine after Gastric Bypass Surgery in a Rat Model.

Alpha-ketoglutarate (AKG) is one of the key metabolites that play a crucial role in cellular energy metabolism. Bariatric surgery is a life-saving procedure, but it carries many gastrointestinal side effects. The present study investigated the beneficial effects of dietary AKG on the structure, integrity, and absorption surface of the small intestine after bariatric surgery. Male 7-week-old Sprague Dowley rats underwent gastric bypass surgery, after which they received AKG, 0.2 g/kg body weight/day, administered in drinking water for 6 weeks. Changes in small intestinal morphology, including histomorphometric parameters of enteric plexuses, immunolocalization of claudin 3, MarvelD3, occludin and zonula ocludens 1 in the intestinal mucosa, and selected hormones, were evaluated. Proliferation, mucosal and submucosal thickness, number of intestinal villi and Paneth cells, and depth of crypts were increased; however, crypt activity, the absorption surface, the expression of claudin 3, MarvelD3, occludin and zonula ocludens 1 in the intestinal epithelium were decreased after gastric bypass surgery. Alpha-ketoglutarate supplementation partially improved intestinal structural parameters and epithelial integrity in rats undergoing this surgical procedure. Dietary AKG can abolish adverse functional changes in the intestinal mucosa, enteric nervous system, hormonal response, and maintenance of the intestinal barrier that occurred after gastric bypass surgery.

Milk Formula Enriched with Sodium Butyrate Influences Small Intestine Contractility in Neonatal Pigs.

Butyrate, a by-product of gut bacteria fermentation as well as the digestion of fat in mother's milk, exerts a wide spectrum of beneficial effects in the gastrointestinal tissues. The present study aimed to determine the effects of sodium butyrate on small intestine contractility in neonatal piglets. Piglets were fed milk formula alone (group C) or milk formula supplemented with sodium butyrate (group B). After a 7-day treatment period, isometric recordings of whole-thickness segments of the duodenum and middle jejunum were obtained by electric field stimulation under the influence of increasing doses of Ach (acetylocholine) in the presence of TTX (tetrodotoxin) and atropine. Moreover, structural properties of the intestinal wall were assessed, together with the expression of cholinergic and muscarinic receptors (M1 and M2). In both intestinal segments (duodenum and middle jejunum), EFS (electric field stimulation) impulses resulted in increased contractility and amplitude of contractions in group B compared to group C. Additionally, exposure to dietary butyrate led to a significant increase in tunica muscularis thickness in the duodenum, while mitotic and apoptotic indices were increased in the middle jejunum. The expression of M1 and M2 receptors in the middle jejunum was significantly higher after butyrate treatment. The results indicate increased cholinergic signaling and small intestinal growth and renewal in response to feeding with milk formula enriched with sodium butyrate in neonatal piglets.

Difference in Performance of EPI Pigs Fed Either Lipase-Predigested or Creon®-Supplemented Semielemental Diet.

Pancreatic enzyme replacement therapy (PERT) and fat predigestion are key in ensuring the optimal growth of patients with cystic fibrosis. Our study attempted to highlight differences between fat predigestion and conventional PERT on body composition of young pigs with exocrine pancreatic insufficiency (EPI). EPI and healthy pigs were fed with high-fat diet for six weeks. During the last two weeks of the study, all pigs received additional nocturnal alimentation with Peptamen AF (PAF) and were divided into three groups: H-healthy pigs receiving PAF; P-EPI pigs receiving PAF+PERT; and L-EPI pigs receiving PAF predigested with an immobilized microbial lipase. Additional nocturnal alimentation increased the body weight gain of EPI pigs with better efficacy in P pigs. Humerus length and area in pigs in groups L and P were lower than that observed in pigs in group H (p value 0.005-0.088). However, bone mineral density and strength were significantly higher in P and L as compared to that of H pigs (p value 0.0026-0.0739). The gut structure was improved in P pigs. The levels of neurospecific proteins measured in the brain were mainly affected in P and less in L pigs as compared to H pigs. The beneficial effects of the nocturnal feeding with the semielemental diet in the prevention of EPI pigs' growth/development retardation are differently modified by PERT or fat predigestion in terms of growth, bone properties, neurospecific protein distribution, and gut structure.

Immune suppression by cyclosporin A inhibits phytohemagglutinin-induced precocious gut maturation in suckling rats.

OBJECTIVES: Enteral exposure to the lectin phytohemagglutinin (PHA) provokes precocious gut maturation in suckling rats coinciding with an early expansion of intestinal mucosal T and B lymphocytes. Here, the role of the immune system in neonatal gut growth and maturation was further studied. MATERIALS AND METHODS: The effects of immunosuppression by cyclosporine A (CyA), 7.5 microg/g of body weight, injected 12 hours before and then daily after the intragastric gavage of PHA, 100 microg/g body weight, to 14-day-old suckling rats were studied after 4 and 12 hours and later after 72 hours. RESULTS: At 4 hours after PHA feeding, an early rapid increase in the intestinal levels of the proinflammatory cytokines interleukin-6, interleukin-1beta, and tumor necrosis factor was obtained, and the CyA treatment did not prevent the temporary PHA-induced intestinal disturbance seen at 12 hours. Later, at 72 hours after PHA gavage the CyA treatment significantly counteracted the PHA-induced gut changes with a decrease in small intestinal growth, a delay in the appearance of adult-phenotype enterocytes in the distal small intestinal, and total inhibition of the PHA-induced pancreas development. Additionally, the increase in plasma level of the acute phase protein, haptoglobin, after PHA feeding was dampened by CyA. CONCLUSIONS: The results indicate that proinflammatory cytokines are involved in the early recruitment of lymphocytes to the gut after PHA challenge, and that the ensuing precocious gut maturation is dependent on activation of the immune system, presumably T cells, in suckling rats.

Amylase-Dependent Regulation of Glucose Metabolism and Insulin/Glucagon Secretion in the Streptozotocin-Induced Diabetic Pig Model and in a Rat Pancreatic Beta-Cell Line, BRIN-BD11.

The current study was aimed at highlighting the role of blood pancreatic amylase in the regulation of glucose homeostasis and insulin secretion in a porcine model of streptozotocin- (STZ-) induced diabetes and in a rat pancreatic beta-cell line, BRIN-BD11. Blood glucose, plasma insulin, and glucagon levels were measured following a duodenal glucose tolerance test (IDGTT), in four pigs with STZ-induced type 2 diabetes (T2D pigs) and in four pigs with STZ-induced type 1 diabetes (T1D pigs). Four intact pigs were used as the control group. The effect of amylase supplementation on both acute and chronic insulin secretion was determined in a BRIN-BD11 cell line. The amylase infusion had no effect on the glucose utilization curve or glucagon levels in the healthy pigs. However, a significant lowering of insulin release was observed in healthy pigs treated with amylase. In the T2D pigs, the glucose utilization curve was significantly lowered in the presence of amylase, while the insulin response curve remained unchanged. Amylase also significantly increased glucagon release during the IDGTT in the T2D and T1D pigs, by between 2- and 4-fold. Amylase did not affect the glucose utilization curve in the T1D pigs. Amylase supplementation significantly decreased both acute and chronic insulin secretion in the BRIN-BD11 cells. These data confirm our previous observations and demonstrate the participation of pancreatic amylase in glucose absorption/utilization. Moreover, the present study clearly highlights the direct impact of pancreatic blood amylase on insulin secretion from pancreatic beta-cells and its interactions with insulin and glucagon secretion in a porcine model.