[The influence of starvation on proliferation kinetics of intestinal mucosa of the mouse large and small intestines].
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Animals↗
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Results for “Intestinal Mucosa”
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[Compensatory hypertrophy of the intestinal mucosa after massive resection of the small intestine].
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Adaptation, Physiological↗
Leukotriene B4 and C4 generation by small intestinal mucosa in children with coeliac disease.
The capacity of the small intestinal mucosa to generate leukotriene B4 (LTB4) and C4 (LTC4) in children with coeliac disease (CD) was investigated by measuring the production of LTB4 and LTC4 in intestinal biopsy specimens after stimulation with 10 microM calcium ionophore A23187. In addition, we examined the relationship between the production of LTB4 and LTC4 in the small intestinal mucosa and symptoms of diarrhoea. LTB4 and LTC4 production was significantly higher in biopsies from patients with active CD than from controls (p < 0.05 and p < 0.01, respectively). There was no significant difference in LTB4 and LTC4 production between patients with inactive CD and controls. In both patients with active CD and controls, no difference in LTB4 and LTC4 production was observed between the patients with and without diarrhoea. These findings suggest that enhanced generation of LTB4 and LTC4 in the small intestinal mucosa may contribute to the pathophysiology of CD but would not be related to the development of diarrhoea.
Calcimycin↗
CCL25 mediates the localization of recently activated CD8alphabeta(+) lymphocytes to the small-intestinal mucosa.
The recruitment of antigen-specific T lymphocytes to the intestinal mucosa is central to the development of an effective mucosal immune response, yet the mechanism by which this process occurs remains to be fully defined. Here we show that the CC chemokine receptor 9 (CCR9) is selectively and functionally expressed on murine alpha(E)beta(7)(+) naive CD8alphabeta(+) lymphocytes and a subset of recently activated CD69(+) CD8alphabeta(+) lymphocytes. Using a T cell receptor transgenic transfer model, we demonstrate that CCR9 expression is functionally maintained on CD8alphabeta(+) lymphocytes following activation in mesenteric lymph nodes but rapidly downregulated on CD8alphabeta(+) lymphocytes activated in peripheral lymph nodes. These recently activated CCR9(+) CD8alphabeta(+) lymphocytes selectively localized to the small-intestinal mucosa, and in vivo neutralization of the CCR9 ligand, CCL25, reduced the ability of these cells to populate the small-intestinal epithelium. Together these results demonstrate an important role for chemokines in the localization of T lymphocytes to the small-intestinal mucosa and suggest that targeting CCL25 and/or CCR9 may provide a means to selectively modulate small-intestinal immune responses.
Adoptive Transfer↗
Fecal intestinal alkaline phosphatase: a parameter for toxic damage of the small intestinal mucosa.
An immunoprecipitation procedure is presented for the measurement of rat intestinal alkaline phosphatase (I-AP) in feces. Controls exhibit a logarithmic normal distribution of fecal I-AP. Single administration of an agent toxic for small intestinal mucosa like bleomycin or triparanol induces an increase of fecal I-AP on the 1st day and a marked reduction of I-AP activity on the following 3 days. After the 5th day, abnormal high fecal I-AP activities were observed during regeneration. In parallel, morphometry and measurements of I-AP activity in the homogenate of small intestinal mucosa were performed. Rat fecal I-AP excretion proved to be a simple, non-invasive, sensitive marker for toxic damage of the small intestinal mucosa.
Alkaline Phosphatase↗
Aminotripeptidase, a cytosol enzyme from rabbit intestinal mucosa.
Aminotripeptidase, a cytosol enzyme from rabbit intestinal mucosa, was purified to homogeneity. The pure enzyme is a glycoprotein containing a very small amount of sugar. It is composed of only one subunit of 50,000 mol. wt. and possesses 1 zinc atom per molecule. Its specificity is primarily directed towards tripeptides with an N-terminal proline residue. However, the enzyme is also able to hydrolyse other tripeptides, except those with either a charged amino acid in the N-terminal position or a proline residue in the second position. The purified aminotripeptidase accounts for almost all the tripeptidase activity of the soluble fraction from intestinal mucosa.
Aminopeptidases↗
Adenosine is a vasodilator in the intestinal mucosa.
The vasoactivity of adenosine in the intestinal mucosa of anesthetized dogs was determined using two experimental techniques. By use of the microsphere technique, infusion of adenosine (1 mumol/min ia) was found to increase significantly venous outflow and mucosal and muscularis blood flows in both jejunum (+77, +72, and +78%) and ileum (+111, +146, and +71%). In constant flow jejunal preparations, intra-arterial adenosine significantly decreased perfusion pressure (-32%), an index of vascular resistance, but did not significantly alter the blood flow distribution between the mucosa and muscularis as determined by microspheres. Thus adenosine equally dilated the mucosal and muscularis vasculatures. Using the second experimental technique, we found that local mucosal application of adenosine or non-metabolizable adenosine analogues [N6-cyclohexyladenosine or 5'-(N-ethylcarboxamido)-adenosine] dose dependently increased jejunal venous outflow. Almost all of the adenosine absorbed from the lumen was localized in the mucosal tissue, suggesting that the above hyperemia resulted from exposure of the mucosal vasculature to these compounds. The hyperemia produced by the luminal placement was not mediated by stimulation of the mucosal nerves, because the hyperemia was unaltered after treating the mucosal surface with a local anesthetic. The present results demonstrate therefore that adenosine is a vasodilator in the canine intestinal mucosa.
Adenosine↗
Diaglycerol biosynthesis in everted sacs of rat intestinal mucosa.
The molecular specificity in the biosynthesis of diacylglycerols by rat intestinal mucosa was examined by means of radioactive markers, thin-layer chromatography with silver nitrate and gas-liquid chromatography with radioactivity monitoring. Bile salt micelles of alternately labeled monoacyglycerols and free fatty acids were incubated with everted sacs of intestinal mucosa for various periods of time and the diacylglycerols were isolated by solvent extraction and thin-layer chromatography. Sterospecific analyses of the X-1,2-diacylglycerols labeled from 2-monoacylglycerols showed that the sn-1,2-isomers (45-55%) were slightly in excess of the sn-2,3-isomers (34-45%) with the X-1,3-diacylglycerols accounting for the rest of the radioactivity (5-10%). This suggests that racemic diacylglycerols may be intermediates in the resynthesis of dietary fat in rat intestinal mucosa. Detailed analyses of the molecular species of the sn-1,2-diacylglycerols labeled from free fatty acids revealed that 10-45% of the total did not contain the acid present in the 2-monoacylglycerol supplied, and therefore had originated from the phosphatidic acid pathway. These findings are at variance with those obtained in isolated microsomes, which have suggested an inhibition of the phosphatidic acid pathway by monoacylglycerols as well as have given evidence of an exclusive synthesis of sn-1,2-diacylglycerols from 2-monoacylglycerols.
Animals↗
Fatty acid omega and (omega-1)-Hydroxylation in rabbit intestinal mucosa microsomes.
The microsomes from rabbit intestinal mucosa which had been washed quickly and thoroughly with phenylmethylsulfonyl fluoride were found to catalyze the hydroxylation of fatty acids in the presence of NADPH and molecular oxygen. Myristic and palmitic acids were converted to the corresponding omega-and (omega-1)-hydroxy fatty acids, whereas lauric acid was converted only to 12-hydroxylauric acid, and capric acid, to 9-and 10-hydroxycapric acids together with an unknown polar acid. Among these fatty acids, both myristic and lauric acids appeared to be the most efficient substrates. The inhibition of the hydroxylation by SKF 525-A and carbon monoxide suggested that the activity depended upon cytochrome P-450. The specific activity of the fatty acid hydroxylation was almost constant along the small intestine, while the aminopyrine N-demethylation activity and the cytochrome P-450 content were highest at the proximal end of the intestine and progressively declined toward the caudal end. The cytochrome P-450 was solubilized from the intestinal microsomes and purified by 6-amino-n-hexyl Sepharose 4B chromatography. The partially purified cytochrome P-450 was active in fatty acid hydroxylation in combination with intestinal NADPH-cytochrome c reductase and phosphatidylcholine.
Animals↗
Calcitonin stimulates adenylate cyclase activity, the accumulation of cyclic adenosine 3',5' monophosphate and the release of prostaglandin E2 in rat intestinal mucosa.
Calcitonin stimulates intestinal fluid and electrolyte secretion by an unclear mechanism. The present results show that synthetic salmon calcitonin significantly stimulates adenylate cyclase activity in the membranes of rat intestinal mucosal cells. The effect of the hormone was in a dose-dependent manner for a dose range of 10(-9)-10(-7) M. The stimulated enzyme activity was followed by a progressive accumulation of cyclic adenosine 3',5' monophosphate and release of prostaglandin E2 in these cells during a 20 min experimental period of time. These results are discussed, and suggest that the formation of cyclic adenosine 3',5' monophosphate possibly mediates the action of calcitonin on intestinal cell functions.
Adenylyl Cyclases↗
[The significance of the expression of the HSP70 and HSP90 in the intestinal mucosa in scalded rats during early postburn stage].
OBJECTIVE: To investigate the changes in the expression, the tissue contents and the distribution of heat shock protein (HSP) 70 and HSP90 in the intestinal mucosa in scalded rats during early postburn stage and to elucidate the effects of heat shock response of intestinal mucosal cell on burn victim's systemic pathophysiology. METHODS: The scalded rats were taken as the model. ELISA, immunoblotting analysis and immunohistochemical methods were employed to analyze and study the expression, the tissue contents and the distribution and their functional status of HSP70 and HSP90 in the intestinal mucosa. RESULTS: (1) The free HSP70 content in the intestinal mucosa exhibited significantly transient decrease in the early postburn stage. (2) The total contents of HSP70 and HSP90 in the intestinal mucosa increased obviously postburn. (3) There exhibited remarkable heterogeneity of the molecular structure of HSP70 in the intestinal mucosa in the early postburn stage. CONCLUSION: The expression and the changes in the contents and the tissue distribution of the two HSPs in the intestinal mucosal cell might play important roles in the cellular stress reaction of the intestinal mucosa and even in the intestinal barrier functional mechanism.
Animals↗
The role of transforming growth factor beta-2, beta-3 in mediating apoptosis in the murine intestinal mucosa.
BACKGROUND & AIMS: Apoptosis is especially relevant in the gastrointestinal tract because the mammalian intestinal mucosa undergoes continual epithelial regeneration. Most recently, we confirmed the proapoptotic role of endogenous transforming growth factor (TGF)-beta in the developing chick retina as well as in chick ciliary, dorsal root, and spinal motor neurons. In the present study, we determined to establish the role of TGF-beta2 and TGF-beta3 in mediating apoptosis in non-neuronal tissue by analyzing the intestinal mucosa of Tgfbeta2(+/-) and Tgfbeta3(+/-) heterozygous mice. METHODS: Intestinal localization of TGF-beta2 and TGF-beta3 isoforms and antiapoptotic molecules Bcl-xL and Bcl-2 was examined immunocytochemically and by Western blot analysis. Apoptosis was detected by enzyme-linked immunosorbent assay and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling, and proliferation was detected by proliferating cell nuclear antigen stains. RESULTS: TGF-beta2 was detected in endocrine cells, whereas TGF-beta3 was predominantly found in goblet cells. Programmed cell death was significantly reduced in the intestinal mucosa of Tgfbeta2(+/-) and Tgfbeta3(+/-) heterozygous mice. This decrease in apoptosis was accompanied by an increase in villus length; proliferation, however, seemed to remain unchanged. The level of Bcl-xL and Bcl-2 was significantly up-regulated in Tgfbeta2(+/-) and Tgfbeta3(+/-) mice. CONCLUSIONS: Our data show that TGF-beta2 and TGF-beta3 play an important role in mediating apoptosis in the intestinal mucosa and regulating apoptosis-associated proteins Bcl-xL and Bcl-2 in vivo.
Animals↗
Expression of cytochrome P450b and P450e genes in small intestinal mucosa of rats following treatment with phenobarbital, polyhalogenated biphenyls, and organochlorine pesticides.
The expression of cytochromes P450b and P450e genes was studied in the small intestinal mucosa of rats using a cDNA which recognizes the mRNAs of both cytochromes as well as oligonucleotide probes which are able to differentiate between the two gene products. Animals were treated with oral and intraperitoneal doses of phenobarbital, gamma-chlordane, trans-non-achlor, and polychlorinated and polybrominated biphenyls. RNA was extracted from small intestinal mucosa and liver. After treatment with each of the compounds, P450b mRNA was markedly induced in small intestinal mucosa and in liver. The greatest degree of induction was found in mucosa of the proximal small intestine where P450b mRNA levels were 4-6-fold higher than levels found in the distal small intestine. This distribution of P450b mRNA was not dependent on the route of administration of inducers. In contrast, although P450e mRNA was induced in the liver after treatment, P450e mRNA in the small intestine did not increase in response to any of the administered inducers. The location of the P450b mRNA within the intestinal mucosa following treatment with inducers was studied by in situ hybridization; the message was induced predominantly in enterocytes located in intestinal villi. These data indicate that the P450b gene is induced in the small intestine following treatment with various xenobiotics and that this induction may be secondary to either transcriptional activation of the gene or to mRNA stabilization in enterocytes located in the villi of the intestinal mucosa. The differential induction of P450b versus P450e genes in the small intestine and liver indicates that the regulation of these closely linked genes is tissue-specific. Furthermore, the marked induction of P450b mRNA in response to the administered xenobiotics indicates that this isoenzyme may have an important biological role in the small intestinal metabolism of environmental toxicants and drugs.
Animals↗
Distribution of dominant T cell receptor beta chains in human intestinal mucosa.
The majority of human intestinal intraepithelial lymphocytes (iIELs) are CD8+ T cells that use the T cell receptor (TCR)-alpha/beta. Previous studies have shown that iIELs isolated from segments of small intestine or colon contain one or several dominant alpha/beta T cell clones. It is not known whether these clones expand only locally in response to a particular antigen or whether they are widely distributed throughout the intestine. To address this question, iIELs were purified from near the proximal and distal margins in a series of intestinal resections for noninflammatory diseases. TCR-beta expression was then assessed by semiquantitative polymerase chain reaction amplification, analysis of N-region length, and DNA sequencing. The previously described oligoclonal expansion of iIELs was confirmed in each sample. Identical dominant clones were identified in the proximal and distal samples from most cases, including samples taken from sites as distant as the transverse and sigmoid colon or rectum. Distinct clones were found in only one case with samples from the terminal ileum and transverse colon. These results demonstrate that a relatively small number of widely dispersed T cell clones comprise the majority of cells in the human intestinal mucosa.
Adult↗
Disease-dependent adhesion of lactic acid bacteria to the human intestinal mucosa.
Their adhesion to the intestinal mucosa is considered one of the main reasons for the beneficial health effects of specific lactic acid bacteria (LAB). However, the influence of disease on the mucosal adhesion is largely unknown. Adhesion of selected LAB to resected colonic tissue and mucus was determined in patients with three major intestinal diseases (i.e., diverticulitis, rectal carcinoma, and inflammatory bowel disease) and compared to healthy control tissue. All strains were observed to adhere better to immobilized mucus than to whole intestinal tissue. Two strains (Lactobacillus rhamnosus strain GG and L. reuteri) were found to exhibit disease-specific adhesion to intestinal tissue. All tested strains, with the exception of L. rhamnosus strain GG, displayed disease-specific adhesion to intestinal mucus. These results suggest that strains with optimal binding characteristics for a particular intestinal disease can be selected.
Adult↗
Mentha piperita (Linn) leaf extract provides protection against radiation induced alterations in intestinal mucosa of Swiss albino mice.
Intestinal protection in mice against radiation injury by M. piperita (1 g/kg body weight/day) was studied from day 1 to day 20 after whole body gamma irradiation (8 Gy). Villus height, goblet cells/villus section, total cells, mitotic cells and dead cells/crypt section in the jejunum are good parameters for the assessment of radiation damage. There was significant decrease in the villus height, number of total cells and mitotic cells/crypt section, whereas goblet cells and dead cells showed significant increase after irradiation. Mentha pretreatment resulted in a significant increase in villus height, total cells and mitotic cells, whereas goblet cells and dead cells showed a significant decrease from respective irradiated controls at each autopsy day. The results suggest that Mentha pretreatment provides protection against radiation induced alterations in intestinal mucosa of Swiss albino mice.
Animals↗
Glycosphingolipid patterns of fetal and adult small intestinal mucosa in the sheep.
The ganglioside and neutral glycosphingolipid composition of fetal and adult sheep small intestinal mucosa were characterized and compared. Mono- and tetrahexosylceramide were the major neutral glycolipids of both fetal and adult tissue. Fetal mucosa, however, possessed a higher content of monohexosylceramide than its adult counterpart. Similarly, GD1a, GM3 and GM2 were found to be the principal gangliosides in fetal and adult tissue. Adult intestinal mucosa possessed significant amounts of GT1a not present in fetal tissue. Analysis of the hydroxy and nonhydroxy fatty acids as well as the long-chain bases of the major glycosphingolipids revealed differences between these lipophilic components of glycolipids in fetal and adult intestinal mucosa. The results, therefore, indicate that both quantitative and qualitative differences in glycosphingolipid composition exist between fetal and adult sheep small intestinal mucosa.
Animals↗
Purification and properties of hexoasmine isomerase (EC5.3.1.19) from pig intestinal mucosa.
Hexosamine isomerase from pig intestinal mucosa was purified about 70-fold. The aminosugar product of the enzymatic reaction was identified as glucosamine 6-phosphate and amino acid product as glutamic acid. The pH optimum was 7.1 Km for fructose 6-phosphate was 6.3 X 10(-4) mol/1 and for L-glutamine 6.5 X 10(-4) mol/1.
Animals↗