SEARCH · PubMed Health

Results for “Intestinal Mucosa”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources

PubMed1993

Effects of a single pentagastrin injection on diamine oxidase activity in the rat intestinal mucosa.

The effect of a single injection of pentagastrin on diamine oxidase (DAO) activity in the rat intestinal mucosa was examined. The animals of subsequent groups were sacrificed by decapitation at 6, 12 and 24 h after the administration of pentagastrin or 0.9% NaCl (controls). Diamine oxidase activity was also tested in entire animals. The intestinal fragments were rinsed with 0.9% NaCl. The mucosal scrapings were frozen in liquid nitrogen. Diamine oxidase activity increased in the 24 h after the administration of pentagastrin, when compared with respective controls. No significant differences at other times were evident. The present data are in agreement with the hypothesis that DAO is an enzyme involved in the negative feedback control mechanism of intestinal mucosa cell proliferation.

Amine Oxidase (Copper-Containing)↗

PubMed1990

Disaccharidases activity in the intestinal mucosa after methotrexate therapy.

Disaccharidases activity in the intestinal mucosa samples of rats was examined after intragastric and intramuscular methotrexate therapy. Methotrexate was given on a twice a week schedule (1 mg/kg body weight). The animals were sacrificed after 2 weeks, 1 month, and 2 months of this therapy. A statistically significant but transient decrease of the lactase and maltase activity was found. The authors suggest studying the beneficial effect of low disaccharidase diet in the first period of methotrexate therapy in children treated with methotrexate.

Administration, Oral↗

PubMed1989

[The production of epidermal growth factor and polypeptides similar to it in the intestinal mucosa of rats in 1,2-dimethylhydrazine-induced carcinogenesis and compensatory regeneration].

The production of EGF and EGF-like polypeptides in the normal intestinal mucosa and during 1,2-dimethylhydrazine (DMH)-induced carcinogenesis and postresection regeneration was studied in albino rats using chromatographic separation of acid-ethanol extracts. Fractions after gel filtration on Biogel P-60 with subsequent reverse-phase high performance liquid chromatography in acetonitrile gradient were tested in radioreceptor assay for competition with EGF. It has been established that intestinal tumours induced by DMH and regenerating intestinal mucosa have amplified production of EGF--alpha-TGF and related proteins of high molecular weight (approx. 30; 45-55; 120 kD) with the EGF-competitive activity. It is supposed that the high molecular weight EGF-competitive material represents nonprocessed forms of EGF and/or alpha-TGF which are accumulated in rapidly proliferating low-differentiated cells due to the intensified expression of their genes.

1,2-Dimethylhydrazine↗

PubMed1995

Epidermal growth factor enhances repair of rat intestinal mucosa damaged by oral administration of methotrexate.

To examine the trophic effect of epidermal growth factor on the rat small intestine, we measured diamine oxidase and ornithine decarboxylase activities in intestinal mucosa injured by methotrexate. Methotrexate was infused orally via a gastric tube at a dose of 10 mg/kg per day on 3 successive days (days 1-3). Epidermal growth factor was injected intraperitoneally at a dose of 40 micrograms/kg per day on 4 successive days following methotrexate infusion (days 4-7). Methotrexate caused a marked decrease in diamine oxidase activity; this decrease returned to a normal level on day 13 in controls. In rats injected with epidermal growth factor, diamine oxidase activity began to recover earlier than in the controls, and returned to a normal level on day 11. Epidermal growth factor enhanced the increase of ornithine decarboxylase activity in mucosa injured by methotrexate. When the increase of ornithine decarboxylase activity was suppressed by alpha-difluoromethylornithine, epidermal growth factor failed to facilitate the repair of intestinal mucosa. These results indicate that epidermal growth factor enhances intestinal repair following methotrexate infusion, and that this effect is mediated, at least in part, by ornithine decarboxylase. It is proposed that epidermal growth factor can be used clinically as a means to enhance mucosal repair of the intestine after chemotherapy with methotrexate.

Administration, Oral↗

PubMed2000

Effect of mesodiencephalic modulation on small intestinal mucosa after massive blood loss in rats.

Effect of mesodiencephalic modulation on small intestinal mucosa was studied in rats subjected to massive blood loss. Massive blood loss induced structural changes in intestinal epitheliocytes typical of tissue hypoxia: intraintestinal edema, mitochondrial alterations, and microcirculation disturbances. A single session of mesodiencephalic stimulation carried out 60 min after massive blood loss produced a pronounced adaptive effect, restored disturbed structure of the intestinal villi, and induced compensatory hypertrophy of the mitochondria. This suggests that mesodiencephalic modulation promotes normalization of intracellular energy metabolism, improves the absorption capacity of bordered enterocytes, and restores the disturbed intestinal barrier.

Adaptation, Physiological↗

PubMedDate not supplied

Enantioselectivity of microsomal and cytosolic esterases in rat intestinal mucosa.

Enantioselectivity of esterases, contained in 9,000g supernatant fraction (S9) prepared from homogenate of small intestinal mucosa of male Sprague-Dawley rats and the subsequent 105,000g supernatant (cytosol) and pellet (microsomes) prepared from S9, was studied using racemic oxazepam 3-acetate (rac-OXA) as the substrate. Esterases in S9 were enantioselective in hydrolyzing either S-OXA or R-OXA, depending on a particular subcellular preparation. Cytosolic and microsomal esterases had opposite enantioselectivity and selectively hydrolyzed S-OXA and R-OXA, respectively. Enantioselectivity of esterases solubilized from microsomes with Triton X-100 (0.1%, w/v) was identical to that of the membrane-bound microsomal esterases. Cytosolic esterases were more sensitive to temperature than either solubilized or membrane-bound microsomal esterases. In the presence of paraoxon (1 microM), the esterases selective toward R-OXA in both microsomes and S9 were completely inhibited, whereas the esterases selective toward S-OXA in cytosol were inhibited by approximately 6%. These results indicate that cytosolic and microsomal esterases in rat small intestinal mucosa are distinctly different enzymes, with opposite enantioselectivity in the hydrolysis of rac-OXA.

Animals↗

PubMed1983

Concentrations of ampicillin plus sulbactam in serum and intestinal mucosa and effects on the colonic microflora in patients undergoing colorectal surgery.

Ampicillin and sulbactam were administered intravenously in 2 g and 1 g doses respectively every 8 h for two days to ten patients undergoing colorectal surgery. Drug concentrations were determined in serum, intestinal mucosa and faeces. The first dose was given at induction of anesthesia. The serum half-life was 2.1 h for ampicillin and 2.0 h for sulbactam on the first day. The concentrations in intestinal mucosa were in most cases 50% or more of the serum concentrations and there was no statistical difference between the two drugs. Faecal concentrations of both drugs were found in eight patients: a mean of 10.5 micrograms/g for ampicillin and a mean of 7.5 micrograms/g for sulbactam. Faecal samples were also collected during the investigation period for culture of aerobic and anaerobic bacteria. Among the aerobic bacteria enterococci, streptococci and enterobacteria decreased markedly during the prophylaxis period. Anaerobic bacteria were also suppressed significantly during the same period. The changes in colonic microflora were related to the concentrations of ampicillin and sulbactam in the intestinal mucosa and faeces. Overgrowth of yeasts was observed in six patients and overgrowth of Pseudomonas fluorescens in two others. These strains were resistant to the combination ampicillin and sulbactam. The microflora normalized in all patients after two weeks. No postoperative infections occurred.

Aged↗

PubMed1996

A common TCR beta-chain expressed by CD8+ intestinal mucosa T cells in ulcerative colitis.

The human intestine contains two populations of anatomically distinct T cells, intraepithelial lymphocytes and lamina propria lymphocytes (LPLs), both of which preferentially use the TCR-alpha beta. Recent studies of TCR alpha- and beta-chain usage by intestinal intraepithelial lymphocytes, which are predominantly CD8+ T cells, have demonstrated that these cells are oligoclonal in normal intestine. This report examined the TCR beta-chains expressed by purified CD4+ and CD8+ T cells from normal colonic lamina propria and from the intestinal mucosa of patients with active ulcerative colitis (UC). The selective expansion of CD8+ T cell clones, and to a lesser extent CD4+ T cell clones, was observed among both normal LPLs and mucosal T cells in UC. These expanded LPL clones from normal donors were all distinct, but the mucosal T cells isolated from five of nine patients with UC contained CD8+ T cells expressing related V beta 3-J beta 1.6 TCRs. These observations provide evidence for an Ag-specific mucosal T cell response in UC. Further studies will be required to identify this Ag and address whether the T cell response to it plays a primary role in initiating the disease or is secondary to the inflammatory response.

Amino Acid Sequence↗

PubMed1990

Glutathione S-transferase subunit induction patterns of Brussels sprouts, allyl isothiocyanate and goitrin in rat liver and small intestinal mucosa: a new approach for the identification of inducing xenobiotics.

Effects of Brussels sprouts (2.5-30%), allyl isothiocyanate (0.03 and 0.1%) and goitrin (0.02%), in the diet, on the glutathione S-transferase subunit pattern in the liver and small intestinal mucosa of male Fisher rats were investigated. A statistically significant linear relationship was found between the amount of Brussels sprouts in the diet and the induction of glutathione S-transferase subunits in two experiments. Increases in total activity of glutathione S-transferases towards 1-chloro-2,4-dinitrobenzene ranged from about 15% (2.5% Brussels sprouts in the diet) to 180% (30% Brussels sprouts in the diet) in the liver, and from 3% (2.5% Brussels sprouts) to 150% (30% Brussels sprouts) in the small intestinal mucosa. There were similar increases in the total amounts of glutathione S-transferase subunits. In the first experiment, when the average sinigrin and progoitrin levels found in the sprouts were 1835 and 415 mumol/kg, respectively, subunit induction patterns in both the liver and the small intestinal mucosa were very similar to the pattern observed after feeding allyl isothiocyanate. In the second experiment, when the average sinigrin level found in the sprouts was as low as the progoitrin level (both about 540 mumol/kg), a goitrin-like induction pattern was observed. The most pronounced difference between the glutathione S-transferase subunit induction patterns due to administration of allyl isothiocyanate and goitrin is the much stronger enhancement of subunit 2 by allyl isothiocyanate. The induction patterns of both experiments indicate that in Brussels sprouts at least two compounds, probably allyl isothiocyanate and goitrin, are responsible for the induction of glutathione S-transferases.

Animals↗

PubMed1981

Cell volume regulation in goldfish intestinal mucosa.

1. Ion and water content of goldfish intestinal mucosa, stripped free from muscular layers were measured under various incubation conditions. 2. Ouabain induces an increase in cation content that is electrically compensated for by chloride. The increase in solute content is accompanied by an increase in water content. 3. When extracellular chloride is partially replaced by sulphate, ouabain does induce cell shrinkage. 4. Anoxia induces a rapid increase in cell volume that is restored by oxygenation of the incubation solution. Ouabain prevents the restoration of volume. 5. It is concluded that the classical ouabain-sensitive Na/K pump participates in the maintenance of cellular volume. We suggest that the constancy in volume after ouabain poisoning as is reported for many tissues might be due to a low chloride conductance of its membranes. 6. Anisotonic media (range: 0.6-1.2 isotonicity), made by variation on mannitol concentration, induce changes in cell water content that deviates from the simplified van't Hoff equation by about 10%. No change in water content after the initial increase was found. 7. We conclude that goldfish enterocytes do not possess a mechanism for rapid volume readjustment.

Anaerobiosis↗

PubMed1998

Expression of the VLA family of integrins in coeliac intestinal mucosa.

The integrins, a family of cell surface proteins, mediate cell adhesion and may influence within the intestinal mucosa processes such as migration and/or proliferation and differentiation of enterocytes and lymphocytes. The aim of this study was to examine the distribution pattern of integrin subunits (VLA alpha1, alpha2, alpha3, alpha4, alpha5, alpha6, beta1 chains) in normal intestinal mucosa and in that of patients with active coeliac disease (CD) and CD in remission. Immunohistochemical techniques and double immunostainings with monoclonal antibodies were used for investigation of the VLA alpha family of integrins and beta1 chain distribution. While the majority of the findings are consistent with the few data previously reported in the literature, surprising is the finding of a lack of expression of VLAalpha1 on the intraepithelial lymphocytes in the coeliac mucosa. The deficient VLA alpha1 expression on IEL in coeliac but not in normal mucosa may imply a genetic variation or a specific deficiency of gene expression during T cell differentiation and activation.

Antibodies, Monoclonal↗

PubMed2003

[Expression of pro-inflammation cytokines and activation of nuclear factor kappab in the intestinal mucosa of mice with ulcerative colitis].

OBJECTIVE: To investigate the expression of pro-inflammation cytokines and activation of nuclear factor kappaB (NF-kappaB) in mouse models of ulcerative colitis. METHODS: Mouse models of ulcerative colitis were established by oral administration of 5% dextran sulfate sodium for 7 d, and the expression of tumor necrosis factor (TNF)- alpha and interleukin (IL)-1beta in the intestinal mucosa were detected by semi-quantitative reverse transcriptional (RT) PCR. The activation of NF-kappaB in the intestinal mucosa was evaluated by electrophoretic mobility shift assay (EMSA). RESULTS: The expressions of TNF-alpha and IL-1beta were increased in the intestinal mucosa (P=0.009), and the nuclear binding activity of NF-kappaB was also up-regulated after the onset of colitis. CONCLUSION: Pro-inflammatory cytokines play important roles in the pathogenesis of UC, and may exacerbate the inflammation of the intestinal mocosa and cause apoptosis of the epithelial cells, possibly under the regulation of NF-kappaB activation.

Animals↗

PubMed1976

Morphometric and autoradiographic investigation of the small and large intestinal mucosa of rats with chronic experimental renal insufficiency.

Following a previous study with experimental short-term, high-grade uremia the changes of the small and large intestinal mucosa of rats with surgically induced chronic renal insufficiency were analysed. A clear tendency to inhibition of the rate of the physiological cell regeneration by prolongation of the mitotic cycle in correlation to the degree of renal insufficiency could be demonstrated. There was a extension of the generation time up to 40% in ileum and up to 50% in the large intestine in the animal group with the relatively highest degree of renal insufficiency. This extension was mainly due to a prolongation of the postmitotic Gi-phase. At the same time the total number of crypt epithelia and of the regenerative cells in the enlarged crypts increased. The enlargement of the regenerative crypt population is interpreted as an adaptive compensation of the inhibition of the cell production by prolongation of the mitotic cycle. A damage of the differentiated surface epithelium could not be detected. The significance of the present results and their relationship to so-called uremic entero-colitis and to sprue-like changes of small intestinal mucosa in man is discussed.

Animals↗

PubMed1983

A family of phosphohydrolases from bovine intestinal mucosa: 5'-nucleotidase.

Bovine intestinal 5'-nucleotidase has been partially purified and characterized for comparison with two other phosphohydrolases from the same tissue, alkaline phosphatase and 5'-nucleotide phosphodiesterase, which are closely related structurally and mechanistically. Kinetic studies with a variety of nucleotides and phosphonate analogs show that, although 5'-nucleotidase is a monoesterase like alkaline phosphatase, it more closely resembles 5'-nucleotide phosphodiesterase in its high affinity and specificity for nucleotide binding. 5'-Nucleotidase is bound very strongly by an affinity column containing a bound phosphonate analog of ADP but is not bound by an affinity column containing a non nucleotide phosphonate which selectively binds alkaline phosphatase. 5'-Nucleotidase is strongly bound by immobilized antibodies prepared against 5'-nucleotide phosphodiesterase, and is less strongly bound by immobilized antibodies prepared against alkaline phosphatase. We conclude that 5'-nucleotidase is structurally more similar to 5'-nucleotide phosphodiesterase than to another monoesterase, alkaline phosphatase.

5'-Nucleotidase↗

PubMed1996

Ornithine decarboxylase activity in rat intestinal mucosa and liver is stimulated by central administration of 2-deoxy-D-glucose but not of 2,5-anhydro-D-mannitol.

It has been shown that 2-deoxy-D-glucose (2-DG) inhibits glucose utilization and elicits feeding through the lateral hypothalamus. In contrast, 2,5-anhydro-D-mannitol (2,5-AM), blocking glycogenolysis and/or gluconeogenesis, elicits feeding through the ventromedial hypothalamus. The aim of the present study was to determine whether ornithine decarboxylase (ODC) activity in the rat small intestine is stimulated by infusion into the third ventricle of 2-DG or of 2,5-AM. Under anesthesia, a cannula was implanted into the third ventricle one week before the experiment. Each rat was infused with 6, 12, and 24 mumol 2-DG or 2,5-AM into the third ventricle without disturbing the behavior. Ingestive behavior was observed for one h after the infusion. ODC activity in the intestinal mucosa and the liver was measured 2 h after the infusion. Additionally, ODC activity was measured in vagotomized rats. Both test solutions elicit feeding at 24 mumol/rat. Infusion of 2-DG into the cerebroventricle significantly increased ODC activity in the duodenal and jejunal mucosa and the liver. In contrast to 2-DG, infusion of 2,5-AM did not increase ODC activity in the intestinal mucosa or liver. Truncal vagotomy attenuated the increase of ODC activity in the intestinal mucosa and liver induced by 2-DG. The present study showed that 2-DG, but not 2,5-AM, increased ODC activity in the peripheral organs, indicating that glucose-metabolism at specific sites of the central nervous system, including the lateral hypothalamus, is important for stimulatory signals to ODC activity. It is also indicated that the stimulatory signals from the central nervous system are mediated, at least in part, via the efferent vagal nerve.

Animals↗

PubMed1977

The presence and distribution of beta-galactosidases in the small intestinal mucosa of the neonatal dog.

The beta-galactosidase activity of the small intestinal mucosa of the neonatal dog has been studied over the pH range 3-0 - 5-8 using different substrates and in the presence and absence of p-chloromercuribenzoate. Partial separation of two beta-galactosidases has been achieved by gel filtration. The results suggest that three beta-galactosidases, comparable with those in other mammals, exist in canine small intestinal mucosa.

Animals↗

PubMed1982

Purification and properties of a neutral endodeoxyribonuclease from rat small intestinal mucosa.

An endodeoxyribonuclease has been purified to near homogeneity from rat small intestinal mucosa by a procedure involving Con A-Sepharose affinity chromatography. During the initial steps of purification, the presence of 5 mM CaCl2 was essential for stability of the enzyme activity. The enzyme has a molecular weight of 32 000 and an isoelectric point of 4.7. NaCl, sulfhydryl reagents, and iodoacetate strongly inhibited the reaction, but tRNA did not. The enzyme required divalent cations for activity and had a pH optimum of pH 6.2 with Co2+ and pH 7.7 with Mn2+. In both optimum conditions, the enzyme hydrolyzed native DNA more rapidly than denatured DNA, and the average chain lengths of limit digestion products of native and denatured DNA were 8 and 10, respectively, at pH 6.2 and 9 and 11, respectively, at pH 7.7. The enzyme activity to produce acid-soluble fractions from linear DNA substrate was similar in the two optimum conditions, but the activity to nick double-stranded, superhelical circular DNA substrate was significantly higher at pH 6.2 than at pH 7.7. The endonuclease formed single-strand breaks making 5'-phosphoryl and 3'-hydroxyl termini, and deoxythymidine was present at the 5' termini with a frequency of about 50% in both optimum conditions. Bovine pancreatic DNase I antibody and G-action inhibited the enzyme activity. Thus this endonuclease is classified as a DNase I.

Animals↗

PubMed1992

A surface energy analysis of mucoadhesion: contact angle measurements on polycarbophil and pig intestinal mucosa in physiologically relevant fluids.

The possible role of surface energy thermodynamics in mucoadhesion was investigated with Polycarbophil and pig intestinal mucosa. In separate experiments, the surface energy parameters of the substrate (mucosa) and the adhesive (polymer film) were determined by contact angle measurements on captive air/octane bubbles in three physiologically relevant test fluids (isotonic saline, artificial gastric fluid, and artificial intestinal fluid). Whereas the swollen Polycarbophil films were relatively hydrophilic as indicated by small water contact angles (22, 23, and 16 degrees), the water contact angles measured on mucosal tissue were significantly larger (61, 48, and 57 degrees). Hence, mucus was found to possess an appreciable hydrophobicity. The measured adhesive performance (force of detachment) between Polycarbophil and pig small intestinal mucosa was highest in nonbuffered saline medium, intermediate in gastric fluid, and minimal in intestinal fluid. In agreement with this trend, the mismatch in surface polarities between substrate and adhesive, calculated from the contact angle data, increased in the same order.

Acrylic Resins↗