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PubMed1971

A paediatric tube and capsule for suction biopsy of the small intestinal mucosa designed for direct nasogastric intubation.

The use of a modified paediatric tube and capsule for suction biopsy of the mucosa of the small intestine is discussed. The tube is small in diameter and can be introduced through the nose without local trauma and with minimal discomfort. The intubation technique was followed in 72 instances to obtain suction biopsies from the proximal mucosa of the small intestine in protein-calorie malnourished children, and the results obtained with this instrument are also presented.

Biopsy↗

PubMed1970

The difference in sensitivity to cardiac steroids of (Na++K+)-stimulated ATPase and amino acid transport in the intestinal mucosa of the rat and other species.

1. The effect of various cardioactive steroids on the activity of a microsomal (Na(+) + K(+))-activated ATPase from rat intestinal mucosa has been studied and compared with their effects on L-phenylalanine and D-galactose transport by rings of rat intestine in vitro. A similar comparison between the sensitivities to ouabain of microsomal (Na(+) + K(+))-ATPase and of phenylalanine transport in the intestines of the mouse, guinea-pig and toad has been made.2. The rat intestinal enzyme is 50% inhibited by a concentration of 1 x 10(-4)M ouabain, 1 x 10(-5)M scillaren A and 4 x 10(-6)M scilliroside. At concentrations which almost completely inhibit the (Na(+) + K(+))-ATPase activity, these steroids have no effect on the transport of phenylalanine or galactose by the rat intestine. Only at concentrations of 1 x 10(-3)M are scillaren A and scilliroside able to reduce phenylalanine accumulation significantly, the same concentration of ouabain being effective only in the absence of external potassium ions. Digitoxin, 1 x 10(-4)M, a comparatively apolar glycoside, had no action on phenylalanine transport in the rat intestine.3. The effect of ouabain on the (Na(+) + K(+))-ATPase and phenylalanine transport system in the mouse intestine is completely analogous to its effect on these parameters in the rat.4. A half-maximal inhibition of guinea-pig intestinal (Na(+) + K(+))-ATPase by ouabain occurs at an inhibitor concentration of 2 x 10(-6)M, but phenylalanine transport by this tissue is only half-maximally reduced at a concentration of 3 x 10(-5)M. Similarly, in the rabbit intestine, there appears to be a difference of an order of magnitude between the sensitivities of the two parameters.5. In the toad, 50% inhibition of the enzymic activity is observed at a concentration of 3 x 10(-5)M ouabain, whereas a concentration of 8 x 10(-4)M is required to reduce phenylalanine accumulation by one half.6. These findings are consistent with the suggestion that an (Na(+) + K(+))-stimulated ATPase is not the only enzyme in the epithelial cells of the intestinal mucosa that is responsible for sodium extrusion (the mechanism for sodium extrusion being intimately coupled with the mechanism for active amino acid transport); therefore, a second, as yet unidentified, enzyme system must be postulated to account for bulk sodium flow through the intestine.

Adenosine Triphosphatases↗

PubMed1983

Factors influencing pyrroline 5-carboxylate synthesis from glutamate by rat intestinal mucosa mitochondria.

Factors influencing pyrroline 5-carboxylate (P5C) synthesis from glutamate by a subcellular fraction enriched in mitochondria of rat small intestinal mucosa have been studied. P5C synthesis decreased rapidly if this subcellular fraction was preincubated at 20 degrees C in the absence of substrates; this effect suggests that the enzyme(s) catalyzing P5C synthesis from glutamate (P5C synthase) is unstable in the absence of substrates. In the presence of substrates P5C synthesis increased linearly for the first 30 min of incubation, suggesting that the substrates promote enzyme stability. Pyridoxal 5'-phosphate is an effective inhibitor of P5C synthase whereas pyridoxamine 5'-phosphate and pyridoxal are not inhibitory. Potassium phosphate, KCl, and KBr each inhibited P5C synthase but potassium-Hepes (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) did not. Potassium phosphate was the most potent inhibitor followed by KBr, and then KCl. These results suggest P5C synthase is sensitive to anion inhibition. Both L-ornithine and D-ornithine inhibited P5C synthase; L-proline did not inhibit. Several analogs of ornithine and proline were also tested and none was found to inhibit P5C synthase; the inhibition by ornithine is, therefore, rather specific and it may prove to contribute to the regulation of metabolism of these amino acids.

Animals↗

PubMed1983

Brush border Mg2+-HCO-3-ATPase, supernatant carbonic anhydrase and other enzyme activities isolated from rat intestinal mucosa: effect of adrenalectomy and aldosterone administration.

The possible role of Mg2+-HCO3-ATPase, carbonic anhydrase and several other enzymes in rat intestinal mucosa as mediators of the action of aldosterone has been examined. The small-intestinal tract was cut into seven segments, 15 cm each in length and the mucosa was scraped off, homogenized in 50 mM D-mannitol-2 mM Tris-HCl buffer (pH 7.1), differentially fractionated and a crude brush border was obtained. The mucosa from the colon and rectum was combined and used as the large-intestinal sample. Five days after the adrenalectomy, activities of brush border Mg2+-HCO3-ATPase and supernatant carbonic anhydrase from the upper small intestine decreased to about 60 and 40% of normal values, respectively. Activities of Na+-K+-ATPase, beta-glycerophosphatase and succinate dehydrogenase were all decreased. Two and 4 h after i.p. injection of aldosterone (40 micrograms/kg) to adrenalectomized rats, all enzyme activities increased except for Na+-K+-ATPase in the upper small intestine. In contrast, Mg2+-HCO-3-ATPase and carbonic anhydrase activities were unchanged 3 h after i.p. injection of dexamethasone (200 micrograms and 1 mg/kg). The activation of both Mg2+-HCO3-ATPase and carbonic anhydrase by a single injection of aldosterone was blocked by pretreatment with cycloheximide (1 mg/kg). These results suggest that aldosterone may induce the synthesis of enzyme proteins in the intestinal mucosa.

Adenosine Triphosphatases↗

PubMed1986

Rat liver and intestinal mucosa differ in the developmental pattern and hormonal regulation of carbamoyl-phosphate synthetase I and ornithine carbamoyl transferase gene expression.

cDNA probes were employed to measure levels of carbamoyl-phosphate synthetase I (CPS) and ornithine carbamoyltransferase (OCT) mRNAs in fetal and neonatal livers and intestines. In the fetal liver, significant levels of OCT mRNA were present at 15-days gestation while CPS mRNA could not be detected until day 17 of fetal development. Apart from a small decline just after birth, amounts of both mRNAs increased steadily to reach adult levels in postnatal life. In contrast to the situation in liver, CPS and OCT mRNA levels in the fetal intestine rose rapidly to peak at day 21 of gestation and then declined steadily in the first seven days after birth. Using the methyl-sensitive restriction isoschizomeric pair, MspI/HpaII, the 5' ends of both the CPS and OCT genes were shown to undergo demethylation during development. In the case of the OCT gene, however, the hypomethylation characteristic of the adult liver and intestinal mucosa was not observed in the 15-day-old fetal liver, where significant levels of gene expression had already been established. Levels of CPS and OCT mRNA in livers of adults responded to glucagon in normal animals (1.5-fold and 2.2-fold increases, respectively) and to dexamethasone in experimentally induced diabetic animals (3-fold increase in CPS mRNA with no change in OCT mRNA). These treatments were all without effect on the levels of CPS and OCT mRNA in intestinal mucosa.

Animals↗

PubMed2001

Glutathione S-transferases in small intestinal mucosa of patients with coeliac disease.

Patients with villous atrophy due to coeliac disease have an increased risk of developing small intestinal malignancies. Intestinal glutathione (GSH) and glutathione S-transferases (GST) are involved in the protection against carcinogenesis. The aim of this study was to evaluate GSH content and GST enzyme activity in small intestinal mucosa of untreated coeliacs compared to controls. We evaluated GSH content and GST enzyme activity, including the levels of GST classes alpha, mu, pi and theta, in small intestinal biopsies of untreated coeliacs (flat mucosa, Marsh IIIC, n = 12) compared to normal subjects (n = 23). Next, we evaluated GSH and GST's in coeliacs in remission (Marsh 0 - I, n = 11), coeliacs with persisting villous atrophy while on a gluten-free diet (partial villous atrophy, Marsh IIIA (n = 5); subtotal villous atrophy, Marsh IIIB (n = 6)) and patients with infiltrative / crypt-hyperplastic Marsh II lesions (n = 4). Total GST enzyme activity and content of GSTalpha are markedly suppressed in Marsh IIIC lesions compared to controls (resp. 220 +/- 79 vs. 464 +/- 189 nmol / mg protein*min (P < 0.001) and 2.79 +/- 2.46 vs. 6.47 +/- 2.29 mg / mg protein (P < 0.001)). In coeliacs in remission these levels normalized. Total GST enzyme activity and GSTalpha levels are proportionately lowered according to the degree of mucosal pathology in Marsh II, IIIA and IIIB. (Spearman's sigma correlation coefficient for total GST, -0.596, P < 0.001; GSTalpha, -0.620, P < 0.001). GSTmu, pi and theta and GSH levels are not significantly different in the selected study groups of mucosal pathology compared to controls. Total GST enzyme activity and content of GSTalpha in small intestinal mucosa are significantly lower in untreated coeliac disease compared to controls. In Marsh II, IIIA and IIIB, GST enzyme activity and GSTalpha content are proportionally lower according to the degree of mucosal pathology. Normal values are seen in coeliacs in remission. This correlation between coeliac disease and a suppressed GSH / GST detoxification system may explain in part the carcinogenic risk in untreated coeliac disease.

Adult↗

PubMed1990

Apolipoprotein B-100: immunolocalization and synthesis in human intestinal mucosa.

Despite the evidence that the human small intestine produces two separate species of apoB mRNA encoding for B-100 and B-48, there is a paucity of data concerning the expression of the latter form in this organ. Using a high resolution immunogold approach, with specific polyclonal antibodies and a panel of monoclonal antibodies (2D8, 3A10, 4G3), both forms of apoB (B-48 and B-100) were revealed over enterocytes of pediatric intestinal samples. Intense labeling was observed over microvilli, apical smooth membrane vesicles, multivesicular bodies, the basolateral membrane, as well as the trans Golgi region. Only low labeling was found over the rough endoplasmic reticulum (rER). Similar patterns of apoB distribution characterized both duodenal and jejunal regions. The presence of labeling over the Golgi apparatus and rER suggests a synthetic activity of both forms of apoB by the epithelial cells. To test this hypothesis, human intestine was incubated with [3H]leucine, homogenized, and subjected to immunoprecipitation for apoB. Immunoprecipitates contained radioactivity mainly in apoB-48 with relatively small amounts in apoB-100 when examined by NaDodSO4-polyacrylamide gel electrophoresis. These findings were further supported by the biochemical determination of apoB-100 and apoB-48 in chylomicron particles isolated from thoracic duct lymph of a human donor. Taken together, our data suggest that the human intestine is able to synthesize and to express the apoB-100.

Apolipoprotein B-100↗

PubMed1982

[Ultrastructural changes in the nerve endings in the large intestine mucosa in Sonne dysentery].

Biopsies of the large intestine of patients with dysentery due to Shigella sonnei were examined. Electron microscopy examinations showed changes in nerve endings in the stroma of the mucous membrane to correlate with the intensity of general histopathological lesions in it. Changes in the nervous apparatus may be of reversible, structural-functional nature in mild cases of the disease or become irreversible in the structures providing transformation and transmission of the nervous signal in synaptic parts of neurites.

Biopsy↗

PubMed1975

Localization of immunoglobulins in intestinal mucosa and the production of secretory antibodies in response to intraluminal administration of bacterial antigens in the preruminant calf.

Immunofluorescent studies of intestinal tissues from young preruminant calves demonstrate the presence of two main populations of immunocytes synthesizing IgA and IgM. These cells had infiltrated the lamina propria of the intestine as early as 4 days of age. There was little evidence of any significant involvement of IgG1 in intestinal immune synthesis of calves at this age although activity was demonstrable in the ileum and colon of one calf. In general there were more IgG2-synthesizing cells than IgG1, but these were few compared with the main populations of IgA and IgM cells. Local antigenic stimulus to the intestinal mucosa of young fistulated calves using extracts of heat-killed Gram-negative bacteria produced antibody in the secretions over a period of approximately 3 weeks. A second administration of a similar antigenic dose produced a similar response indicating the requirement for continuous stimuli to maintain a measurable level of antibody secretion. Gel filtration and antiglobulin assays indicated that the antibacterial activity was predominantly associated with IgA and that IgM also played a significant role. Oral administration of bacterial antigens to colostrum-fed calves from 5 to 8 days of age produced a faecal antibody response, indicating that intestinal secretion could be successfully interrelated with the declining passive antibody to maintain an almost continuous level of intestinal antibody in early life.

Administration, Oral↗

PubMedDate not supplied

[Effect of radioprotective agents on the epithelium of small intestine mucosa in irradiated animals].

In experiments on irradiated (10 Gy) mice a study was made of the morphological changes in the small intestine mucosa and in its functional status estimated by absorption of stain uranine. It was shown that the preventive administration of cystamine and S-(omega)-aminopropyl-beta-aminoethylthiophosphoric acid to the exposed mice increased the proliferation processes in the crypt and the cell movement per villus providing a favourable effect of the radioprotective agents on the absorption function.

Animals↗

PubMed2001

Effectiveness of denuding the intestinal mucosa by submucosal injection in the porcine model.

PURPOSE: Lack of mucosal regrowth on denuded bowel segments is considered a prerequisite for successful grafting of cultured urothelial cells for bladder augmentation. This study was designed to establish a technique for clean and complete de-epithelialization of the intestinal mucosa. MATERIALS AND METHODS: A segment of the small bowel was isolated in six microminipigs. The isolated segment was detubularized and the submucosa injected with HEPES-buffered saline, elevating the mucosa from the underlying tissue and allowing removal with ease. One portion was resected and, along with a portion of the removed mucosa and a sample of the full-thickness bowel, submitted for histologic evaluation. Another portion of the bowel segment remained denuded while the final denuded segment was covered with polyglactin mesh. After 3 days, 1 week, and 3 weeks, specimens from each of the bowel segments were collected for histologic assessment. Immunoperoxidase labeling was performed to confirm the presence or absence of mucosal regrowth. RESULTS: All intestinal segments showed no mucosal regrowth at the 3-day, 1-week, and 3-week incubation periods. Minimal reaction between the denuded bowel segment and the mesh was evident in all of the pigs. CONCLUSIONS: In the porcine model, intestinal mucosa can be removed completely using submucosal injection. This technique may be useful in future clinical studies involving bladder augmentation using denuded bowel.

Animals↗

PubMed1993

Histopathology of the small intestinal mucosa in Nematodirus spathiger infection in rabbits.

Rabbits were experimentally infected with two levels (5000 and 17,000) infective larvae of Nematodirus spathiger. Histological (villus length, mucosa to serosa ratio, crypt surface) and biochemical (protein content, alkaline phosphatase and leucine aminopeptidase activities) measurements relating to the small intestinal mucosa were examined along the entire length of the organ. In the proximal intestine, the presence of worms was associated with villus abrasion, increased crypt surface and decreased alkaline phosphatase and leucine aminopeptidase activities. Conversely, beyond the main site of infection in the distal small intestine, some signs of hypertrophied villi and crypts were noted without any changes in enzyme activities. These distal variations were similar to those previously described in experimental Trichostrongylus colubriformis infections of rabbits. These results tend to confirm the use of the rabbit as an experimental model to study Nematodirus infection. They also suggest that the distal adaptive process in the nematode-parasitized small intestine could occur independently of the worm species.

Alkaline Phosphatase↗

PubMed2001

[Morphofunctional changes in the small intestinal mucosa in dynamics of physiological pregnancy and lactation].

Histostructural changes of small intestine mucosa of intact, pregnant and lactating rats were studied by optic and electron microscopy and morphometry. Increase of mucosa thickness, vili height, crypt depth, quantity of enterocytes and crypts were studied in dynamics of pregnancy. Period of lactation that followed labour was characterized by opposite processes, i.e. decrease of above mentioned parameters, which became identical to that in control animals.

Female↗

PubMed1980

[Quantitative changes in glucocorticoid binding capacity of blood plasma, liver and small intestine mucosa following consumption of various dietary proteins].

Studies on corticosteroid binding proteins in blood plasma, cytoplasm, and nuclei of cells from liver and mucosa of the small intestine of growing rats were carried out under the influence of different protein diets. Increasing protein quality induced higher growth rates and an increase of the glucocorticoid binding capacity as well as the concentration of total and free corticosterone in blood plasma and increasing contents of specific corticosteroid binding receptors in the cytoplasm and nuclei of cells from liver and mucosa of the small intestine. In the cytoplasm the bound fraction takes only 5 to 10% of the total hormone concentration, compared to 80 to 90% in blood plasma. These findings suggest that the changes in the concentration of specific hormone binding proteins may be a general principle of the effect of dietary protein in the regulation of metabolism.

Animals↗

PubMed1981

Magnified observations of the intestinal mucosa.

Before and after dispersal of glucose, aminoacid and fat solutions, the intestinal mucosa was observed by a magnifying endoscope, dissecting microscope and scanning electron microscope (SEM). Minimal changes were observed after dispersal of 5% glucose, 20% sucrose and 10% artificial fat solutions, while, moderate to severe changes in shape, color and surface epithelium were recognized after dispersal of 12% aminoacid and 20% glucose solutions. These differences in the changes were thought to be caused not only by the characteristic differences in the solutions but also by the differences in osmotic pressure of the solutions. In intestinal examinations, dissecting microscopes and SeM can be used concomitantly with observations by the magnifying endoscope.

Animals↗

PubMed2000

Upregulation of HGF activator inhibitor type 1 but not type 2 along with regeneration of intestinal mucosa.

Hepatocyte growth factor (HGF) activator inhibitor type 1 (HAI-1) and type 2 (HAI-2) are new Kunitz-type serine protease inhibitors that were recently purified and cloned from the human stomach cancer cell line MKN45 as specific inhibitors against HGF activator. Both proteins contain two Kunitz inhibitor domains and are expressed abundantly throughout the gastrointestinal tract, in addition to the placenta, pancreas, and kidney. In this study, to assess the possible roles of HAI-1 and HAI-2 in the intestinal mucosa, we examined the expression of HAI-1 and HAI-2 during regeneration of the intestinal mucosa. Immunohistochemical studies revealed that HAI-1 but not HAI-2 was detected more strongly in regenerative epithelium than in normal epithelium, although both proteins were detected throughout the human gastrointestinal tract. During the course of acetic acid-induced experimental colitis in an in vivo mouse model, HAI-1 but not HAI-2 was upregulated in the recovery phase, suggesting that HAI-1 but not HAI-2 is associated with the regeneration of damaged colonic mucosa. Upregulation of HAI-1 may serve to downregulate the proliferative response after initial activation of MET receptor by HGF/scatter factor after an injury.

Acetic Acid↗

PubMed1977

[Age characteristics in vascularization of the intestinal mucosa].

The authors examined age peculiarities in the microcirculation bed of the intestinal mucosa in 20 individuals, aged from 0 to 83 years. The vessels were manifested by injection with Indian ink-gelatine mass. There was also complication of their angioarthitectonics parallel to the age and progressive thickening of glandular layer and enlargement and clongation of the villi. The arterial sources were increased and varified. Villus-capillary nest was changed in vertical direction. Togethe with this the outflow venous system was complicated as over the basal plexus a second venous plexus was formed-over the basis of the villi. The mucosa was enriched with arterio-venous anastomosis. Maximal development of the microcirculatory system was found at the end of the third decade, after which their reduction begins. This process was more manifested after the sixth decade, when the blood vessels were folded and received uneven constructions and dilatations, and then the capillary nest is rearranged and simplified.

Adolescent↗

PubMed1998

Urokinase and the intestinal mucosa: evidence for a role in epithelial cell turnover.

BACKGROUND: The functions of urokinase in intestinal epithelia are unknown. AIMS: To determine the relation of urokinase expressed by intestinal epithelial cells to their position in the crypt-villus/surface axis and of mucosal urokinase activity to epithelial proliferative kinetics in the distal colon. METHODS: Urokinase expression was examined immunohistochemically in human intestinal mucosa. Urokinase activity was measured colorimetrically in epithelial cells isolated sequentially from the crypt-villus axis of the rat small intestine. In separate experiments, urokinase activity and epithelial kinetics (measured stathmokinetically) were measured in homogenates of distal colonic mucosa of 14 groups of eight rats fed diets known to alter epithelial turnover. RESULTS: From the crypt base, an ascending gradient of expression and activity of urokinase was associated with the epithelial cells. Median mucosal urokinase activities in each of the dietary groups of rats correlated positively with autologous median number of metaphase arrests per crypt (r=0.68; p<0.005) and per 100 crypt cells (r=0.75; p<0.001), but not with crypt column height. CONCLUSIONS: Localisation of an enzyme capable of leading to digestion of cell substratum in the region where cells are loosely attached to their basement membrane, and the association of its activity with indexes of cell turnover, suggest a role for urokinase in facilitating epithelial cell loss in the intestine.

Animals↗