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At least 73 records · Page 4Linked to original sources
PubMed1986

Ontogeny of the Thy-1-, Lyt-2+ murine intestinal intraepithelial lymphocyte. Characterization of a unique population of thymus-independent cytotoxic effector cells in the intestinal mucosa.

Murine intestinal intraepithelial lymphocytes (IEL) from unprimed thymus-bearing and athymic nude mice were characterized according to the expression of murine lymphocyte antigenic markers and cytotoxic activity. The majority of IEL from thymus-bearing mice were Lyt-2+, L3T4- lymphocytes, over half of which did not express Thy-1 surface antigens. Nude IEL and spleen cells were void of Thy-1+ cells; however, Lyt-2 antigens were expressed on a significant proportion of IEL, but not splenic lymphocytes. Overall, 40-70% of IEL from either thymus-bearing or athymic mice expressed the cytotoxic activation antigen, CT-1, and the J11d lymphocyte marker, both of which were associated with a population of Thy-1-, Lyt-2+ cytotoxic IEL. These data are taken to mean that the intestinal epithelium is a site uniquely enriched for activated cytotoxic cells, a significant proportion of which originate as non-thymus-derived lymphocytes with acquired lytic activity.

Animals↗
PubMed1979

Effect of the pesticides phosalone and lindane on the activity of some dipeptidases and disaccharidases in rat intestinal mucosa.

The intestinal dipeptidase and disaccharidase activities were investigated in 120 male albino rats of the Wistar strain after administration of 21 mumol.kg-1 body weight phosalone, 14.8 mumol.kg-1 body weight lindane and 10.5 mumol.kg-1 body weight phosalone combined with 7.4 mumol.kg-1 body weight lindane. The dipeptidase activity under the effect of these comparatively low doses of pesticides reveals slightly to moderate changes. The activity of intestinal disaccharidases after a 90-day phosalone and lindane treatment is markedly decreased, particularly that of sucrase. The mechanism of these changes remains unknown.

Animals↗
PubMed1992

Platelet-activating factor (PAF-acether) formation in neonatal intestinal mucosa and in cultured intestinal epithelial cells.

We report the presence of platelet-activating factor (PAF-acether; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) in small-intestinal and colonic mucosa of neonatal rats. The PAF-acether content was higher in the colon than in the small intestine, and was lower in the small intestine of 30-day-old animals than in 14-day-old animals. We also report that cultured intestinal epithelial cells (INT 407) produce PAF-acether when stimulated with the calcium ionophore A23187, and that homogenized INT 407 cells can degrade PAF-acether with the formation of lysoPAF-acether. These findings suggest that intestinal epithelial cells are able to produce and metabolize PAF-acether, a potent mediator of inflammation. The authors propose that this might contribute to the pathophysiology of inflammatory bowel disease.

Animals↗
PubMed1983

Studies on the histogenesis of the tunica mucosa of the small and large intestines of the camel (Camelus dromedarius). I. Histogenesis of the small intestinal mucosa.

The histogenesis of the small intestinal mucosa passes through a previllous stage, comprising development until the formation of villi (at a C RL of about 15 cm), and a villous stage, comprising the further development. In the previllous stage, the mucosa consists of a Lamina epithelialis made up of undifferentiated cells with stratified nuclei and a Lamina propria/submucosa made up of homogeneous mesenchyme. The villi appear as luminal epithelial outgrowths associated with vascularized mesenchymal stalks and their growth advances in a cranio-caudal direction. The intestinal glands were firstly observed at the 26 cm-stage as downgrowths of the intervillous epithelium into the underlying mesenchyme.

Animals↗
PubMed1998

[Effect of mast cell activation on microcirculation of intestinal mucosa in inflamed small intestine of the rat].

Intravital microscopy and FITC-labeled erythrocytes were used to investigate villous perfusion in the rat small intestine in a model of inflammatory bowel disease. Inflammation was induced with s.c. application of Indomethacin. It has previously been demonstrated that systemic Indomethacin leads to an increase in villous blood flow in the small intestine of the rat. In order to determine whether mast cell activation may contribute to the increase in villous perfusion, Ketotifen was used to inhibit mast cell degranulation. We found that Ketotifen significantly reduced villous perfusion in the inflamed intestine, but had no effect in the control group. We conclude that mast cell activation is one of the mechanisms leading to hyperemia in the mucosa of the small intestine in this animal model. Further studies are required to determine whether mast cell stabilizers may be beneficial in the treatment of inflammatory bowel disease in man.

Animals↗
PubMed1993

Effect of oxidant exposure on thiol status in the intestinal mucosa.

The intestinal epithelium is likely to be exposed to oxidants derived from diet, bacterial metabolic products or endogenously formed cellular metabolites. Glutathione, being the major intracellular thiol, provides protection against oxidative injury. The present study looks at the effect of luminal exposure to oxidants on intestinal thiol status. Different oxidants were placed in the lumen of anesthetized rats for 30 min and the mucosal non-protein and protein-bound thiols were quantitated using HPLC. Oxidant exposure altered the thiol redox status and increased the oxidized glutathione (GSSG) level 6-7-fold and protein-bound reduced glutathione (GSH) 2-fold, whereas the non-protein GSH level remained the same or increased slightly. This could be due to either increased mucosal GSH synthesis or transport from circulation. After incubation with buthionine sulfoximine, a specific inhibitor of GSH synthesis, prior to oxidant exposure, the same increase in GSSG and GSH in the mucosa was seen. Oxidant exposure also decreased the plasma GSH level by 50%. The other cellular non-protein thiols, cysteine and cystine, did not change after luminal exposure to oxidants. These results suggest that oxidant exposure stimulates uptake of GSH from the circulation to maintain mucosal GSH.

Animals↗
PubMed1979

Hydrolysis of ester-type drugs by the purified esterase from human intestinal mucosa.

Esterase from human intestinal mucosa was purified 210 fold by solubilization with Triton X-100, chromatography on DEAE-cellulose, Sephadex G-100 and hydroxylapatite, and isoelectric focusing. The purified esterase showed a single band by polyacrylamide gel electrophoresis. The molecular weight of the purified esterase was estimated to be about 55,000 by gel filtration on Sephadex G-150, and the isoelectric point was 5.02. The purified esterase was strongly inhibited by diethyl p-nitrophenyl phosphate (E-600) and diisopropyl fluorophosphate (DFP), and was not inhibited by eserine sulfate and p-chloromercuribenzoate. The purified esterase from human intestinal mucosa was found to be one of the carboxylesterases. The purified esterase hydrolyzed ester-type drugs, i.e., aspirin, clofibrate, indanyl carbenicillin and procaine, but did not hydrolyze amide-type drugs and choline-type drugs.

Aspirin↗
PubMed1983

Mg2+-HCO-3-ATPase and carbonic anhydrase in rat intestinal mucosa.

Mg2+-dependent and HCO-3-stimulated ATPase activity was highest in the brush border (microvilli) of rat duodenal mucosa compared with that of the other gastrointestinal mucosa. This ATPase may be useful to neutralize the gastric acid in the duodenal lumen. Carbonic anhydrase seems to accomplish a subsidiary role in the above reaction.

Adenosine Triphosphatases↗
PubMed1988

Oral administration of epidermal growth factor in suckling rats stimulates cell DNA synthesis in fundic and antral gastric mucosae as well as in intestinal mucosa and pancreas.

The effect of orogastrically given epidermal growth factor (EGF) on the on the development of the digestive system was examined in suckling rats. In particular, DNA synthesis in progenitor cells of the fundic, antral and ileal mucosae and of the exocrine pancreas was analyzed through tritiated thymidine injection and histoautoradiographic study. EGF (10 or 100 micrograms/kg, 3 times daily) was instilled in pups between the 11th and the 13th day of life. Controls received distilled water in a similar manner. All rats were killed 14th after the last orogastric instillation and 45 min after one pulse injection of tritiated thymidine. The highest dose of EGF increased the antral mucosal height (P less than 0.005), the mean number of epithelial cells per crypt column in ileal mucosa, as well as the cell labeling indices of fundic, antral, ileal mucosae and of pancreatic acinar tissue (P less than 0.001) as compared with controls. The lowest dose of EGF increased the cell labeling indices of antral and ileal mucosae and of the exocrine pancreas (P less than 0.001) but did not modify that of fundic mucosa as compared with controls. It is concluded that (a) orally given EGF stimulates cell proliferation in the digestive system of suckling rats, (b) antral mucosa is more sensitive to EGF than fundic mucosa, (c) it is likely that EGF is absorbed and acts systemically on the pancreas. It remains to be determined whether EGF acts systemically or by activation of luminal receptors, on fundic, antral and ileal mucosae.

Administration, Oral↗
PubMed1987

[Epitheliocytes of fundal glands and the relative volume of the parietal microflora of the stomach and small intestine mucosa in experimental chronic duodenal ulcer].

The effect of experimental chronic duodenal ulcers and vagotomy on fundal gland epitheliocytes and membrane microflora has been studied in rats using light microscopy and stereometry on semithin sections. It is shown that in ulcers the relative amount of perietal and zymogen cells increases, while the volume of mucocytes decreases. Vagotomy leads to a decrease in the relative amount of parietal and zymogen cells and increases the relative amount of mucocytes. The relative volume of membrane microflora in gastric fundal and pyloroantral regions, duodenum and jejunum diminishes in ulcers and increases in vagotomy, as compared to the control.

Animals↗
PubMed1980

Electron microscopic studies on the small intestinal mucosa of rats after mechanical intestinal obstruction and ischemia.

Ultrastructural changes in the small intestine during the early phase following mechanical obstruction were compared with those after vascular ligation. In both experiments (the early phase of mechanical ileus and ischemia) intestinal epithelial cells at the tips of villi showed common features. One of the most significant changes was an alteration in microvilli, with fragmentation into vesicles, narrowing of apical microvilli and decrease in number. The other change was fatty degeneration of the epithelial cells, which was accompanied by vesiculation of smooth endoplasmic reticulum beneath the terminal webs, fat deposition and dilated Golgi complex containing fat. These observations suggest that in the early phase of mechanical ileus, ischemic damage plays an important role.

Animals↗
PubMed1985

Antibiotic concentrations in intestinal mucosa.

The concentrations in the intestinal mucosa after the initial dose of cefoxitin, piperacillin and clindamycin have been studied. The antibiotics were given at the induction of anesthesia as prophylaxis to patients undergoing elective colorectal surgery. The concentrations of the antibiotics in serum and intestinal mucosa taken during the operation were determined by the microbiological agar diffusion method. Therapeutic concentrations in intestinal mucosa were maintained during the major part of the operation period. The mean mucosa/serum concentration ratios were for cefoxitin 0.4, for piperacillin 0.5 and for clindamycin 1.2.

Aged↗
PubMed2004

Analysis of gangliosides from carp intestinal mucosa.

The gangliosides of carp intestinal mucosa were isolated and analysed by thin-layer chromatography (TLC), TLC immunostaining test, and TLC/secondary ion mass spectrometry (TLC/SIMS). Four species of gangliosides, designated as G-1, G-2, G-3 and G-4, were separated on TLC. The TLC/SIMS analysis of the G-1 ganglioside of carp intestinal mucosa revealed a series of [M-H](-)ions from m/z 1061 to m/z 1131 representing the molecular mass range of GM4-like ganglioside with NeuAc. G-2, G-3 and G-4 gangliosides were analysed by the TLC immunostaining test. G-2 ganglioside was recognised by the monoclonal antibody specific for ganglioside GM1 (AGM-1 monoclonal antibody). However, G-3 ganglioside migrating on TLC between GM3 and GM1 ganglioside was not recognised by anti-GM3 monoclonal antibody and by AGM-1 monoclonal antibody. Furthermore, G-4 ganglioside with a similar TLC mobility as GD1a ganglioside did not show the reactivity to the anti-GD1a monoclonal antibody. In addition using the AGM-1 monoclonal antibody, the expression of GM1 ganglioside in the carp intestinal tissue was studied. GM1 ganglioside was detected on the epithelial cell surface of carp intestinal mucosa.

Animals↗