Adult ; Female ; Gases ; Humans ; Intestine, Small ; metabolism ; microbiology ; physiology ; Liver Cirrhosis ; metabolism ; microbiology ; Male ; Middle Aged

Intestinal tract, which produces more than fifty kinds of gut peptides, is regarded as the largest endocrine organ. With regard to the gut peptides, a number of studies were focused on their structure, function and the roles in some diseases. The changes in output or distribution of gut peptides in the intestinal tract during development have been largely unknown. This study was aimed to investigate the changes of somatostatin (SST) and somatostatin receptor 2 (SSTR2) in small intestinal and hepatic tissues during the development of macaque. The tissue samples of small intestine, liver or blood samples from peripheral and portal vein of 4 macaques in 6-month fetus, 2-day neonate, 45-day neonate and adult were obtained after anesthetization. The concentrations of SST in blood or tissues of macaques were measured by radioimmunoassay. The distributions of SST in small intestinal or hepatic tissues were visualized by immunohistochemical staining. The expression of SSTR2 was detected by in situ hybridization. SST concentration of intestinal tissue in 6-month-old macaque was (27.3+/-16.6) ng /mg protein and light positive staining of SST was localized in mucosal crypts but negative in muscle layer. The intestinal concentration of SST increased gradually with macaque development and reached to the peak [(120.1+/-35.3) ng /mg protein] in adult. It was significantly higher than that in fetus (P<0.01). Strong positive staining of SST was found in both mucosal crypts and myenteric nerve plexus of adult animal. SSTR2 was obviously expressed in intestinal epithelium of fetus but its expression was greatly reduced in epithelium and was shifted to mucosal crypts when grown to adult. Negative staining of SSTR2 in muscle layer of fetal or neonatal macaque turned to be positive in myenteric nerve plexus of adult. The levels of SST or SSTR2 in liver decreased gradually during development. SST concentrations of small intestinal tissue kept significantly higher than those of hepatic tissues in the macaque developing stages. SST levels of portal vein were also maintained significantly higher than those of peripheral blood in the macaque developing stages. In conclusion, the level of SST and expression of SSTR2 in mucosal crypt increased gradually with macaque development. SST from intestinal tract was quickly degraded in portal vein before entering into liver. SST positive myenteric nerve plexus was visualized only in mature macaque.
Animals ; Animals, Newborn ; Fetus ; Intestine, Small ; metabolism ; Liver ; metabolism ; Macaca mulatta ; growth & development ; metabolism ; Male ; Receptors, Somatostatin ; metabolism ; Somatostatin ; metabolism

OBJECTIVETo study the transport of glutamine and glucose, expression of their transporters and tissue morphology in intestinal hypoperfusion.

METHODSSprague-Dawley rats were randomized to receive 60 min of intestinal hypoperfusion (superior mesenteric artery clamp) or serve as normoxic controls (celiotomy only). At the same time, jejunal loops were randomized to receive in situ perfusion of mannitol,glucose,or glutamine.Intestinal brush border membrane vesicles (BBMV) were prepared by calcium precipitation. Sodium-dependent uptake of glucose and glutamine into BBMV were quantitated by rapid mixing and filtration. Histologic examination and immunohistochemistry were performed by pathologists blinded to the groups.

RESULTSWhen compared with the control group, tissue lactate concentration of the hypoperfused group increased significantly (4.9+/-0.3 vs 3.1+/-0.2), especially in the glucose perfused groups (P<0.01). Transport and transporters of glucose in brush border, but not glutamine, decreased during hypoperfusion [(76+/-10) pmol d mg(-1) d 10 s(-1) vs (290+/-13)pmol d mg(-1) d 10 s(-1)]. Tissue structural damage was most severe in glucose perfused groups during hypoperfusion.

CONCLUSIONTransport and expression of transporters of glucose and glutamine in enteral nutrition are differently regulated under conditions of trauma and stress.

Animals ; Enteral Nutrition ; Glucose ; metabolism ; Glutamine ; metabolism ; Intestine, Small ; blood supply ; metabolism ; pathology ; Ischemia ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To study the biodegradation properties of multi-laminated small intestinal submucosa (mSIS) through in vitro and in vivo experiments, comparing with Bio-Gide, the most widely used collagen membrane in guided bone regeneration (GBR) technique, for the purpose of providing basis to investigate whether mSIS meets the requirements of GBR in dental clinics. METHODS: The degradation properties were evaluated in vitro and in vivo. In vitro degradation was performed using prepared collagenase solution. Morphology of mSIS and Bio-Gide in degradation solution were observed and the degradation rate was calculated at different time points. In in vivo experiments, nine New Zealand rabbits were used for subcutaneous implantation and were divided into three groups according to observation intervals. Six unconnected subcutaneous pouches were made on the back of each animal and were embedded with mSIS and Bio-Gide respectively. At the end of weeks 4, 8, and 12 after operation, gross observation and HE staining were used to evaluate the degree of degradation and histocompatibility. RESULTS: In vitro degradation experiments showed that mSIS membrane was completely degraded at the end of 12 days, while Bio-Gide was degraded at the end of 7 days. Besides, mSIS maintained its shape for longer time in the degradation solution than Bio-Gide, indicating that mSIS possessed longer degradation time, and had better ability to maintain space than Bio-Gide. In vivo biodegradation indicated that after 4 weeks of implantation, mSIS remained intact. Microscopic observation showed that collagen fibers were continuous with a few inflammatory cells that infiltrated around the membrane. Bio-Gide was basically intact and partially adhered with the surrounding tissues. HE staining showed that collagen fibers were partly fused with surrounding tissues with a small amount of inflammatory cells that infiltrated as well. Eight weeks after operation, mSIS was still intact, and was partly integrated with connective tissues, whereas Bio-Gide membrane was mostly broken and only a few residual fibers could be found under microscope. Only a small amount of mSIS debris could be observed 12 weeks after surgery, and Bio-Gide could hardly be found by naked eye and microscopic observation at the same time. CONCLUSION In vitro degradation time of mSIS is longer than that of Bio-Gide, and the space-maintenance ability of mSIS is better. The in vivo biodegradation time of subcutaneous implantation of mSIS is about 12 weeks and Bio-Gide is about 8 weeks, both of which possess good biocompatibility.
Animals ; Biocompatible Materials/metabolism* ; Bone Regeneration ; Connective Tissue ; Intestinal Mucosa ; Intestine, Small ; Membranes, Artificial ; Rabbits

To study the metabolism of trans-resveratrol-3-O-glucoside (TRG) in vitro in rat tissues, the incubation with cell-free extracts from rat stomach, duodenum, jejunum, ileum and liver was performed, separately. After TRG was incubated with the tissue extracts at 37 degrees C for up to 90 min, the deglycosylation of TRG was (3.50 +/- 0.24) % for stomach, (65.7 +/- 5.94)% for duodenum, (83.5 +/- 6.43)% for jejunum, (77.6 +/- 6.26)% for ileum and (9.62 +/- 1.21)% for liver, separately. It was observed that the small intestine extracts were more active in deglycosylation of TRG than the liver extract, which suggested that the small intestine mucosa played an important role in deglycosylation of TRG. It was assumed that the deglycosylation of TRG was catalyzed by beta-glucosidase in small intestine mucosa.
Animals ; Duodenum ; metabolism ; Female ; Glucosides ; metabolism ; Ileum ; metabolism ; Intestinal Mucosa ; metabolism ; Intestine, Small ; metabolism ; Jejunum ; metabolism ; Liver ; metabolism ; Male ; Rats ; Rats, Wistar ; Stilbenes ; metabolism ; Stomach ; metabolism

Glutamine, the most abundant amino acid in bloodstream, is the preferred fuel source for enterocytes. Glutamine exerts its functions through the activity of its transporters, which are located in cytomembrane, to transport it into or out of intestinal epithelial cells. Intestine is the primary center for glutamine metabolism in the body. As ASCT2 and B(0)AT1 are the most important glutamine transporters in the intestine, it wound be helpful to gain the knowledge of the structure, function, and pathologic changes and control strategy of the two transporters in order to have a better understanding of the metabolism and function of glutamine.
Amino Acid Transport System ASC ; Biological Transport ; Enterocytes ; Epithelial Cells ; metabolism ; pathology ; Glutamine ; metabolism ; Humans ; Intestine, Small ; metabolism

OBJECTIVETo look for the evidences of motilin receptor expression on interstitial cells of Cajal (ICC) of the rabbit.

METHODSmooth muscle segments with ICC were isolated from the small intestine of 10-day old rabbits. The tissue segments equilibrated in Ca(2+)-free Hanks' solution were dispersed with an enzyme solution containing collagenase type II and then Ficoll density centrifugation was used to dissociate ICC. The cells were suspended and cultured in the M199 medium. The c-kit antibody was applied to distinguish the cultured ICC. The motilin receptor was identified by immunocytochemical assay with GPR38 antibody, c-kit antibody and hoechst 33342 combined to label ICC. Cells cultured for a few days were sorted for ICC with c-kit stained green fluorescent through flow cytometry. The total RNA and proteins extracted from the sorted ICC were respectively used to verify motilin receptor on the ICC by reverse-transcriptase polymerase chain reaction (RT-PCR) and Western blotting.

RESULTWe had successfully dissociated and cultured ICC of rabbit small intestine in vitro. Fluorescent staining with c-kit antibody confirmed that the culture ICC was successful. Triple-labeled immunofluorescent staining had detected the motilin receptor on membrane of ICC. Flow cytometry analysis showed that the ratio of c-kit positive cell in the cultured cells was 64.3%. The number of sorted ICC was 6.7 × 10(5) and 5.6 × 10(6). The results of RT-PCR and Western blot confirmed that the ICC had motilin receptor expression.

CONCLUSIONOur study demonstrated presence of motilin receptor on ICC of the rabbit. The present results may suggest that ICC play an important role in gastrointestinal movement induced by motilin.

Animals ; Cells, Cultured ; Interstitial Cells of Cajal ; metabolism ; Intestine, Small ; cytology ; Rabbits ; Receptors, Gastrointestinal Hormone ; metabolism ; Receptors, Neuropeptide ; metabolism

OBJECTIVETo investigate the morphological changes in intestinal villi after severe burns in rats, so as to explore its possible relationship with enteral bacterial translocation.

METHODSFifty Wistar rats were employed in the study, 10 of them were assigned to the control group (C). The rest 40 rats were subjected to 30% TBSA full-thickness scalding (burn group, B). 4 ml/100 g normal saline was given intra-peritoneally to the injured rats. The changes of the caliber of the central chyliferous vessel, the intestinal water content and the mucosal morphology of the terminal ileum were determined in the rats in C group and in B group at 8, 12, 24 and 48 postburn hours. The morphology of villi was observed with scanning electron microscope and light microscope.

RESULTSThe ileal villi appeared normal in C group. The central chyliferous vessel dilated persistently in rats of B group at all postburn time points, and dilatation was more evident in B group compared with control group (P < 0.01). At the same time an abundant amount of lymph was observed in the central chyliferous vessel. The intestinal water contents decreased to (70.5 +/- 2.2)% and (69.5 +/- 3.1)% in rats of B group at 8 and 12 PBHs, respectively, and they were obviously lower than that in C group (76.9 +/- 1.5)%, (P < 0.01). The intestinal water content in B group was similar to that in C group at 24 and 48 PBH (P > 0.05).

CONCLUSIONThe morphological changes in the intestinal villi of rats with severe burn injury may predispose the invasion of enteral toxin and bacteria. Intestinal lymphatics can be an important route for enteral bacterial translocation. The water reabsorption of the intestinal mucosa can be transiently enhanced during early postburn stage.

Animals ; Burns ; metabolism ; pathology ; Intestinal Mucosa ; metabolism ; pathology ; Intestine, Small ; pathology ; Rats ; Rats, Wistar ; Thoracic Duct ; pathology

BACKGROUNDA patented remote controlled capsule (RCC) has recently been developed to provide noninvasive drug delivery to selected sites in the human gut that allows assessment of regional gastrointestinal (GI) drug absorption under a normal physiological environment. The objective of this study was to investigate the rate and extent of aminophylline absorption after site-specific delivery of the drug in the GI tract using RCC and a magnetic marker monitoring (MMM) technique.

METHODSThis study was conducted in twelve healthy male subjects, in a three-treatment, randomized, crossover manner with a 7-day washout. Eligible subjects received a 150 mg aminophylline dose through an oral administration, or via a remote controlled capsule, delivered to the small bowel or ascending colon. MMM was employed to monitor the GI transit of the RCC, and the radio-frequency signal was used to activate capsules at target sites. Blood samples were obtained at regular intervals until 24 hours post dose/activation. Plasma theophylline concentrations were measured by a TDx System Analyzer. A comparison of the PK profile with the oral dosing route of aminophylline was performed after delivery to the small bowel and colon.

RESULTSThe RCC was well tolerated in volunteers. The mean capsule activation time for the small bowel and ascending colon was 2.07 hours and 6.08 hours post dose. Aminophylline had similar absorption profiles from the small bowel compared with the stomach, with an area under the curve (AUC(t)) ratio of 92% vs. the stomach, but a lower absorption profile from the ascending colon, with an AUC(t) ratio of 47.2% vs. the stomach.

CONCLUSIONSThe proprietary of the RCC and MMM technique offer the opportunity to obtain data on the intestinal absorption of a drug in humans under noninvasive conditions. Aminophylline is rapidly and efficiently absorbed from the small bowel. While colonic absorption was limited by the poor water condition although effective absorption was observed from the ascending colon. This provides an opportunity for rational development of modified-release formulations as well as alternative dosage forms.

Adult ; Aminophylline ; administration & dosage ; pharmacokinetics ; Capsules ; administration & dosage ; pharmacokinetics ; Colon ; metabolism ; Humans ; Intestine, Small ; metabolism ; Male ; Young Adult

The miniature pig is a very suitable donor species in xenotransplantation of human organs. Lipid metabolism is an important process that involves the creation and degradation of lipids, which is associated with the function of the gastro-intestinal tract. However, the distribution of lipid metabolism related molecules in the gastro-intestinal tract in the miniature pig is unclear. The present study examined the expression of farnesoid X-receptor (FXR), liver X- receptor (LXR), retinoid X-receptor (RXR), liver fatty acid binding protein (L-FABP), fatty acid synthase (FAS) mRNA in the digestive organs of miniature pigs. FXR and LXR mRNA were not expressed in the stomach but were expressed at high and low density in the small and large intestines, respectively. RXR mRNA was expressed in stomach with moderate density, small intestine with high density and in the large intestine with low density. L-FABP and FAS mRNA were expressed in the stomach and large intestine with low density and in the small intestine with high density. L-FABP mRNA was expressed in the liver and kidney with high density, and in pancreas with low density. FAS mRNA was expressed in the liver with high density, and in pancreas and kidney with low density.
Fatty Acid Synthetase Complex ; Fatty Acid-Binding Proteins ; Humans ; Intestine, Large ; Intestine, Small ; Intestines ; Kidney ; Lipid Metabolism ; Liver ; Pancreas ; RNA, Messenger ; Stomach ; Swine ; Tissue Donors ; Transplantation, Heterologous