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PubMed1983

Effect of pentagastrin on mouse gastric and small intestinal mucosa in vivo and in vitro.

1. Single administration of various doses (62.5, 125, 250, 500 micrograms/kg bodyweight) or multiple administration of a single dose (250 micrograms/kg body wt) of pentagastrin to fasted mice do not alter the protein and DNA content, nor the DNA synthesis in fundus of stomach, distal duodenum, and proximal jejunum. 2. Pentagastrin has also been added at different doses into an organ culture of adult mouse duodenum or jejunum. 3. The explants were taken from animals fasted for 24 or 48 hr before sacrifice. 4. Protein and DNA content, protein and DNA synthesis, activities of several brush border enzymes and morphology have not been modified. 5. Therefore, the drug does not seem to have a direct effect on the mouse intestinal mucosa. 6. These observations are compared to results obtained from other species.

Animals↗
PubMed1996

Influence of dietary spices or their active principles on digestive enzymes of small intestinal mucosa in rats.

A few common spices or their active principles, were examined for their possible influence on digestive enzymes of intestinal mucosa in experimental rat. The animals were fed the following diets for 8 weeks: control, curcumin (0.5%), capsaicin (15 mg%), piperine (20 mg%), ginger (50 mg%), cumin (1.25%), fenugreek (2%), mustard (250 mg%) and asafoetida (250 mg%). Dietary curcumin, capsaicin, piperine and ginger prominantly enhanced intestinal lipase activity and also the disaccharidases sucrase and maltase. Dietary cumin, fenugreek, mustard and asafoetida brought about decreases in the levels of phosphatases and sucrase. The positive influences of a good number of spices on these terminal enzymes of digestive process could be an additional feature of species that are generally well recognized to stimulate digestion.

Amylases↗
PubMed1987

[Apoptosis and regeneration of enterocytes in experimental atrophy of the small intestine mucosa].

Apoptosis, one of the types of cell deaths, participates in regulating the size of regenerated tissue. Severe atrophy of small intestine mucosa in mice was caused by the administration of hydroxyurea solution. The degree of atrophy correlated with a lowering mitotic activity and DNA synthesis in the epithelium of crypts. Apoptotic bodies were situated above the basal membrane, in crypt lumen or were phagocytized by adjacent epithelial cells. The development of atrophy, as well as the regeneration of mucosa can be predicted by the relation between mitosis and apoptosis.

Animals↗
PubMed2005

Biochemical and immunohistochemical analysis of glycosaminoglycans in inflamed and non-inflamed intestinal mucosa of patients with Crohn's disease.

OBJECTIVES: Changes in extracellular matrix glycosaminoglycans (GAGs) of the intestinal mucosa have been associated with inflammatory bowel disease. The aim of the present study was to follow the changes in GAGs metabolism during the progression from non-inflamed to inflamed intestinal colon of patients with Crohn's disease (CD), using direct biochemical analysis and specific immunohistochemistry against chondroitin/dermatan sulfate and heparan sulfate. DESIGN AND METHODS: The content of GAGs from inflamed and non-inflamed colon of eight patients with active CD was estimated by uronic acid per dry weight of tissue and analyzed by agarose gel electrophoresis and ion-exchange chromatography. Intestinal sections were stained using antibodies against dermatan sulfate/chondroitin 4-sulfate (DS/CS), heparan sulfate (HS), and ICAM-1 (CD54), and analyzed by confocal microscopy. RESULTS: There was a reduction in the amount of GAGs in the non-inflamed colon of patients with CD. In the inflamed colon, HS, CS and DS showed increased concentrations compared with the non-inflamed colon. GAGs showed a diffuse distribution in the lamina propria and in the basement membrane of both inflamed and non-inflamed mucosa of patients with CD. CONCLUSION: We observed a marked reduction in GAGs with altered patterns of distribution in the non-inflamed colon of patients with CD. The increase in the synthesis of GAGs observed in the inflamed colon may be a compensatory mechanism for the restoration of the integrity of the intestinal mucosa.

Adult↗
PubMed1982

[Local immunity in acute dysentery. II. The content of antibody-forming cells in the large intestine mucosa in acute Flexner dysentery in the dynamics of the disease].

Antibody-forming cells were detected in the large intestine of patients with acute Flexner's dysentery by means of the modified Jerne - Nordin method of hemolysis in agar. This method allowed one to determine the classes of immunoglobulins produced by the cells contained in tissue microspecimens obtained by the biopsy of the intestinal mucosa. The maximum amount of antibody-containing cells could be detected on days 7-12 of the disease. The content of antibody-forming cells was shown to depend on the severity of dysentery, the duration of the disease and the therapeutic methods used in the process of treatment. IgA was found to be the most frequent antigen type.

Acute Disease↗
PubMed1997

Role of endogenous and exogenous nitric oxide on intestinal mucosa and microflora in the rat.

In the present study the effects of exogenous and endogenous nitric oxide (NO) on intestinal bacteria and on the intestinal tissue integrity have been investigated in healthy rats and in rats receiving bacterial endotoxin (LPS). A segment of jejunum was taken in order to evaluate tissue damage and hematoxylin-eosin staining; microbiological studies were carried out collecting stool samples. Administration of LPS (5 mg kg-1 i.v.) induced a moderate jejunal damage, which was completely prevented by NG-nitro-L-arginine methyl ester (L-NAME), 5 mg kg-1 s.c.), thus suggesting a damage of endogenous NO on the intestinal mucosa; sodium nitroprusside (SNP, 10 mg kg-1 os) reduced significantly jejunal damage induced by LPS. Endogenous NO produced by the administration of LPS resulted to be cytotoxic for all examined aerobic and anaerobic bacteria, while exogenous NO, released from SNP, showed an inhibitory effect only on Entero. faecalis and E. coli growth. From our data, it seems reasonable to conclude that high local levels of NO are required in order to observe jejunal damage and cytotoxic effects on aerobic and anaerobic faecal flora.

Animals↗
PubMed1988

An unidentified inhibitor of lipid peroxidation in intestinal mucosa.

Lipid peroxidation in vitro was tested by malonaldehyde production in gastrointestinal mucosa and compared with other tissues. It was observed that gastrointestinal mucosa was resistant to both non-enzymatic and enzymatic lipid peroxidation. This was due to the presence of an inhibitor of lipid peroxidation in the membranous fractions of intestinal mucosa. This inhibitor was capable of inhibiting other recognised peroxidation systems, such as liver mitochondria. This effect was confirmed by measurement of diene conjugation and utilisation of arachidonic acid as other markers of peroxidation, in addition to malonaldehyde production. Preliminary characterisation of this inhibitor revealed that it is resistant to proteolysis, non-diffusable and extractable from membranes by organic solvents. It was partially purified by methanol extraction of the mucosa and by three successive preparative thin-layer chromatography steps. The purified material gave a single spot on thin-layer chromatography, using a number of different solvent systems. Mobility of the inhibitor on thin-layer chromatography was different from that of authentic tocopherol, and it was present in the intestine of vitamin-E-deficient animals. These results suggest that the resistance of intestinal mucosa to lipid peroxidation is due to the presence of a novel inhibitor which is lipidic in nature.

Animals↗
PubMed1984

Effects of semisynthetic diets on xenobiotic metabolizing enzyme activity and morphology of small intestinal mucosa in humans.

We studied the effects of semisynthetic (elemental) diets on the function and morphology of the human small intestine. The enzymatic capacity of the intestinal mucosa to metabolize lipophilic xenobiotics was investigated using jejunal biopsy specimens from 15 normal subjects who were on an isocaloric, nutritionally balanced semisynthetic diet for 7 days and thereafter on a normal home diet. Each subject underwent biopsy twice: on day 7 of semisynthetic diet and again on home diet 2-6 wk later. The jejunal mucosal tissue was examined by histologic morphometry and stereomicroscopy. Moreover, 25-50 mg of the biopsy material was homogenized and the following enzyme activities were determined in 20,000 g supernatant: for cytochrome P450-dependent monooxygenase activity with 7-ethoxycoumarin O-deethylase (EOD) and with nicotinamide adenine dinucleotide phosphate (NADPH)-cytochrome c reductase and for conjugation activity with 1-naphthol glucuronyltransferase (NGT). The NGT and reductase activities were unchanged by the dietary alterations. However, the EOD activity was significantly depressed on semisynthetic diet and rose to control range on home diet (from 5.3 +/- 2.5 to 12.4 +/- 8.6 pmol/min X 10 mg wet wt). Male subjects had significantly higher EOD activities than female subjects on semisynthetic diet (6.6 +/- 2.3 vs. 3.2 +/- 0.9) as well as on home diet (16.3 +/- 9.0 vs. 6.4 +/- 3.0). Semisynthetic diet also reduced the jejunal villous height significantly when compared with home diet (408 +/- 49 vs. 373 +/- 44 micron). Therefore, on semisynthetic diet the toxicity of dietary xenobiotics that are inactivated by the intestinal mucosa may be increased.

7-Alkoxycoumarin O-Dealkylase↗
PubMed1998

A method for purification and characterisation of Mycobacterium avium subsp. paratuberculosis from the intestinal mucosa of sheep with Johne's disease.

Mycobacterium avium subsp. paratuberculosis, the cause of Johne's disease in ruminants, cannot be cultured in large quantities from affected sheep in Australia. A method is described for the purification of the organism from the intestinal mucosa of sheep with multibacillary Johne's disease in order to undertake restriction fragment length polymorphism (RFLP) analysis for epidemiological purposes. Using sucrose and potassium chloride as separation media for differential and density gradient centrifugation, yields of approximately 90 mg dry weight M. avium subsp. paratuberculosis per 5 g intestinal mucosa were obtained. The preparations of purified M. avium subsp. paratuberculosis were visually free of non-acid fast bacteria and contained 10(2)-10(3) aerobic/ facultatively anaerobic organisms per gram wet weight. DNA extracted from purified M. avium subsp. paratuberculosis was examined by hybridisation with an IS900 probe after digestion with BstEII and RFLP patterns distinct from isolates from cattle were obtained. The RFLP pattern of purified M. avium subsp. paratuberculosis from five sheep matched that obtained previously from organisms cultured from sheep in studies in New Zealand, indicating that the purification and RFLP method is robust.

Animals↗
PubMedDate not supplied

[Decrease in cAMP levels and increase in cGMP levels in the small intestine mucosa after treatment with fluoride].

Sodium fluoride was studied for its effect on the cAMP and cGMP amount in the small intestine mucosa of rats under conditions of acute and chronic experiments. A significant decrease in the cAMP level and an increase in the cGMP level were revealed in both cases. Changes in the content of cyclic nucleotides were followed by marked changes in their physiologically important ratios.

Animals↗
PubMed1976

[Intraepithelial shigellae invasion of the intestinal mucosa in patients suffering from acute Sonne dysentery].

Data are presented on detection of intraepithelial localization of shigellae in the biopsy materials of the large and small intestine mucosa of the patients with various forms of acute Sonne dysentery, in comparison with the clinico-morphological picture of the disease. Biopsy specimens (60 of the large and 7 of the small intestine) were stained with thionine and examined bacterioscopically; an intracellular distribution of the microbes was revealed in 58 cases; in 53 of them a subsequent identification of the microbes by the fluorescent antibody method was carried out; in 47 cases (88.7%) invasion of Sh. sonnei into the cells of the epithelium of the mucosa of the large and the small intestine was confirmed. There proved to be a direct relationship between the severity of the course of the disease, the level of shigellae localization and the extent of contamination by them of the cells of the large intestinal mucosa. The role of the penetrating capacity of shigellae in the development of the pathological process in dysentery is discussed.

Acute Disease↗
PubMed1985

Metabolism of all-trans-retinoic acid and all-trans-retinyl acetate. Demonstration of common physiological metabolites in rat small intestinal mucosa and circulation.

The kinetics and metabolism of physiological doses of all-trans-retinoic acid were examined in blood and small intestinal mucosa of vitamin A-depleted rats. A major portion of intrajugularly injected retinoic acid is rapidly (within 2 min) sequestered by tissues; subsequently 13-cis-retinoic acid and polar metabolites are released into circulation. All-trans-retinoic acid appears in small intestinal epithelium within 2 min after dosing and is the major radioactive compound there for at least 2 h. Retinoyl glucuronide and 13-cis-retinoic acid are early metabolites of all-trans-retinoic acid in the small intestine of bile duct-cannulated rats. Retinoyl glucuronide, the major metabolite of retinoic acid intestinal epithelium, in contrast to other polar metabolites, was not detected in circulation. An examination of [3H]retinyl acetate metabolites under steady state conditions in vitamin A-repleted rats demonstrates the occurrence of all-trans-retinoic acid and 13-cis-retinoic acid in circulation and in intestinal epithelium, in a pattern similar to that found after injection of retinoic acid into vitamin A-depleted rats. Our data establish that all-trans-retinoic acid, 13-cis-retinoic acid, and retinoyl glucuronide are physiological metabolites of vitamin A in target tissues, and therefore are important candidates as mediators of the biological effect of the vitamin.

Animals↗
PubMed2003

Impeded establishment of the infective stage of Trichinella in the intestinal mucosa of mice by passive transfer of an IgA monoclonal antibody.

Our previous study showed that the IgA monoclonal antibody (mAb) HUSM-Tb1 forms immunoprecipitates on the cuticular surface of infective larvae of Trichinella britovi, and that intraperitoneal injection of this mAb to mice 5 hr before challenge infection confers a high level of protection against intestinal T. britovi. The same treatment produced a similar effect in BALB/c mice inoculated orally with Trichinella pseudospiralis larvae, indicating that the effects may be seen upon most members of the genus Trichinella. Worms recovered from the intestinal mucosa at 1 hr after challenge infection with T. pseudospiralis was few in mice passively immunized with the mAb, whereas a substantial number of worms were recovered from the mucosa of control groups. These results suggest that the IgA mAb impedes establishment of infective Trichinella worms in the intestinal mucosa. Trichinella worms inoculated orally into BALB/c mice vaccinated with ultraviolet-irradiated muscle larvae 3 weeks earlier were expelled between days 4 and 7 after challenge infection. Although the mAb HUSM-Tb1 originated from the mesenteric lymph node cells of mice vaccinated repeatedly with such irradiated larvae, IgA-mediated expulsion does not seem to play an important role in this vaccination model.

Animals↗
PubMed2003

Impedance spectroscopy for monitoring ischemic injury in the intestinal mucosa.

This work evaluates the feasibility of monitoring ischemic injury in the gastrointestinal mucosa by impedance spectroscopy, using a minimally invasive intestinal catheter. The disruption of the intestinal mucosa plays a key role in the evolution of shock and is the 'motor of multiple organ failure'. Different technologies have been developed to monitor mucosal perfusion, oxygenation and/or ischemia, but no practical method exists to assess tissue damage, which may be crucial for preventing multiple organ failure. The experimental protocol of this study relied on an isobaric model of hypovolemic shock in 16 anaesthetized rabbits assigned to three groups: sham (n = 6), ischemia (n = 5) and ischemia + reperfusion (n = 5). Complex impedance spectra were recorded in the range of 0.05 to 300 kHz, with simultaneous measurements of tonometric pHi in the ileum every 30 min for 4 h. Impedance spectra were reproducible, and those of tissue under prolonged ischemia were clearly differentiable from those of normally perfused tissue. The dynamic changes in impedance did not correlate directly with either tissue perfusion or pHi, but instead correlated well with the duration of ischemia. It is concluded that impedance spectroscopy does indeed measure changes in tissue injury, and could be a very useful tool to guide therapy of patients in shock.

Animals↗
PubMed1993

Influence of orally administered epidermal growth factor on normal and damaged intestinal mucosa in rats.

The effect of orally administered epidermal growth factor (EGF) on the mucosal growth and hydrolase activity of normal and damaged small intestine was examined in rats. Adult rats fed EGF daily at 10 times the estimated daily intake of EGF from human milk showed increases in specific activity but not total activity of various brush-border hydrolases with unaffected mucosal protein content and villus-to-crypt ratios through day 9. Ingestion of EGF for 13 days resulted in significant decreases in mucosal protein content without changes in villus height or hydrolase activity. The effect of oral EGF on recovery of damaged intestine was studied in rats fed a liquid diet supplemented with EGF at 0, 1, 10, or 20 times the estimated daily intake from human milk after treatment with methotrexate (MTX) to induce acute intestinal injury. Animals treated with MTX showed significant reductions in body weight and small intestinal villus height, mucosal protein content, and hydrolase activities through day 6 posttreatment. Daily ingestion of EGF did not affect the MTX-induced reductions in mucosal protein content and hydrolase activity by day 3 but caused significant increases in mucosal disaccharidase and leucine aminopeptidase activity by day 6 at the 1- or 10-times human milk EGF levels. Similar changes were not observed in MTX-treated rats fed the 20-times human milk level of EGF. These studies suggest that oral EGF is capable of modulating mucosal protein levels and stimulating enterocyte hydrolase expression during repair of the intestinal mucosa.

Administration, Oral↗
PubMed2002

Poly(A)(+) RNA encoding proteins capable of transporting L-methionine and/or DL-2-hydroxy-4-(methylthio) butanoic acid are present in the intestinal mucosa of broilers.

To investigate the presence of poly(A)(+) RNA that encode proteins capable of transporting L-methionine (L-Met) and/or DL-2-hydroxy-4-(methylthio) butanoic acid (HMB), Xenopus oocytes were injected with poly(A)(+) RNA isolated from broiler intestinal mucosa. Healthy oocytes at stage V or VI were collected from Xenopus laevis and microinjected with water, poly(A)(+) RNA or size-fractioned poly(A)(+) RNA. The ability of the injected oocytes to take up either L-Met or HMB was examined by incubating oocytes with [methyl-(3)H]-L-Met or [5-(14)C]-HMB. A greater uptake of L-Met (P < 0.01) and HMB (P < 0.05) by oocytes injected with poly(A)(+) RNA from the duodenum, jejunum and ileum of the small intestine was observed compared with water-injected oocytes. The greatest (P < 0.05) uptake occurred when poly(A)(+) RNA from the jejunum or ileum was injected. Injections from four different pools of sucrose gradient--fractionated poly(A)(+) RNA from all three intestinal segments induced (P < 0.01) L-Met uptake. There were three to four different pools of sucrose gradient--fractionated poly(A)(+) RNA from the duodenum, jejunum and ileum that induced (P < 0.05) HMB uptake. Uptake of HMB was greater at pH 5.5 than at pH 7.5 and was independent of Na(+). Uptake of L-Met induced by all four poly(A)(+) RNA pools decreased dramatically when Na(+) was removed from the uptake buffer, which indicated that the majority of L-Met uptake was Na(+)-dependent. These results indicate that there are multiple sized poly(A)(+) RNA that encode proteins capable of mediated transport of L-Met and/or HMB present in broiler intestinal mucosa.

Animals↗
PubMed1998

Ultrastructural effects of intravascularly injected polyethylene glycol-hemoglobin in intestinal mucosa.

Polyethylene glycol (PEG)-conjugated Hb (PEG-Hb) is being considered as a blood substitute. Previously, we showed that PEG-Hb extravasates rapidly from the intestinal mucosa and causes transient epithelial sloughing, resulting in temporary unimpeded passage of material between the intestinal lumen and the microcirculation. The present study quantifies the time course of factors related to this disturbance. Anesthetized Sprague-Dawley rats (350-450 g) were injected with a bolus of PEG-Hb (10 mg/ml) in saline. Control animals received saline, alone or with Dextran 70 (5 mg/ml). After 2, 8, 15, 60, or 90 min, the small intestine was perfusion fixed for microscopy (4 animals for each time point). Epithelial cell detachment and mucosal mast cell degranulation peaked at 2 and 8-15 min, respectively, but by 90 min were back to normal. Goblet cell secretion increased with time up to 8-15 min, after which it leveled off. Mean interstitial width was significantly greater 8 min after injection than for controls and continued to increase with time. In capillaries, endothelial fenestral diaphragms were replaced by thick, amorphous structures. Mesenteric mast cell degranulation was significantly greater 60-90 min after injection compared with controls. We propose that these results are consistent with intravascular injection of PEG-Hb invoking a transient inflammatory response in the intestine.

Animals↗