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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mast cells are a significant component of the mucosa in the gastrointestinal tract. There is increasing evidence that these cells are involved in the pathophysiology of various intestinal disorders ranging from food allergy to inflammatory bowel disease. When activated, mast cells release a host of potent mediators and cytokines which are capable of inducing pathophysiology. The bulk of the evidence has come from hypersensitivity studies in experimental animals sensitized either by parasitic infection or by active immunization to an antigen using adjuvants which stimulate IgE production. Subsequent antigen challenge of the gut results in mast cell activation associated with alterations in intestinal functions including ion transport and epithelial permeability. Intestinal secretory transport responses are inhibited by antagonists of mast cell mediators and neurotoxins, implicating mast cell-nerve interactions with the epithelium. In genetically mast cell-deficient mice, antigen-induced secretion is reduced approximately 70% and this component is not affected by neural or mast cell inhibitors; adoptive transfer of bone marrow containing mast cell precursors derived from congenic normal mice restores the complete antigen response. These results provide more direct proof that mast cell activation causes abnormal gut function. Recently, we have begun studies which indicate that activation of mast cells induces ion secretion in surgically resected human intestine. Reduced secretory responses in specimens from patients with IBD suggest that mast cells may play a role in the pathophysiology of inflammatory bowel disease.
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PMID:Functional abnormalities in the intestine associated with mucosal mast cell activation. 150 88

Previous retrospective studies of intestinal mucosal mast cells in coeliac disease have given divergent results, and we have recently reported that inappropriate methodology could account for these discrepancies. In this prospective study, mucosal mast cell counts were performed in Carnoy fixed, peroral jejunal biopsy specimens from patients with coeliac disease, both untreated and treated with a gluten-free diet; and from controls (mainly irritable bowel syndrome). Mean mucosal mast cell count in 27 control subjects was 146/mm2, SD 29. Significantly higher values were obtained in untreated coeliac disease (mean 243, SD 41, p less than 0.001) returning to the normal range in coeliacs treated with a gluten-free diet with normal jejunal biopsy morphology. In seven patients mucosal mast cell counts were performed in multiple jejunal biopsies, and these showed that mucosal mast cell distribution was not patchy. There was no evidence of degranulation of intestinal mucosal mast cells under the conditions of routine biopsy (overnight fast). An increase in mucosal mast cells in untreated coeliac disease may be one explanation for the high number of IgE positive stained cells in the intestinal mucosa that has been reported by some authors.
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PMID:Human intestinal mucosal mast cells: expanded population in untreated coeliac disease. 682 6

Interstitial cystitis, a sterile bladder condition, is characterized by urinary frequency, urgency, burning and suprapubic pain. Increasing evidence indicates that interstitial cystitis is a heterogeneous syndrome that reflects an immune response to a variety of triggers. More than 50% of the patients have allergies, 30% have the irritable bowel syndrome and almost 20% suffer from migraine headaches. Increased numbers of mast cells have been reported in interstitial cystitis. Mast cell activation, which is critical if these cells were to be implicated in this syndrome, has been investigated by electron microscopy, which definitively shows mast cell secretion. Recently, methylhistamine, the major metabolite of histamine, and the specific mast cell marker, tryptase, were shown to be significantly elevated in urine of interstitial cystitis patients. Bladder biopsies from 53 patients were analyzed blindly for the number and degree of activation of mast cells using 4 different stains for light microscopy, as well as electron microscopy. Controls included 16 patients with incontinence and chronic bacterial cystitis. Mast cells in controls were less than 10/mm.2 and were all nearly intact. Surprisingly, mast cells from 11 cancer patients averaged 50/mm.2 but almost all were intact. In contrast, mast cells from 26 interstitial cystitis patients averaged 40/mm.2 and more than 90% were activated to various degrees. Therefore, bladder mast cell activation is a characteristic pathological finding in at least a subset of patients with interstitial cystitis.
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PMID:Activation of bladder mast cells in interstitial cystitis: a light and electron microscopic study. 786 1

In a group of 74 patients with irritable colon syndrome the studies were carried out evaluating the frequency of abnormal reactions after meal and positive skin reactions with extracts of inhalatory and alimentary substances, 0.1% histamine and 1% codeine. An assessment was also done of the correlation of skin reactions with the degree of irritability of the large bowel expressed as score. Abnormal reactions after meal were reported by 89% of the studied patients with irritable colon syndrome. All meals giving abnormal reactions after consumption may be the source of allergens and may trigger allergic reactions in predisposed persons, but many of them, in view of the contents of histamine, tyramine, and the ability of release or synthesis and release of mast cell mediators, may cause reactions of pseudoallergic mechanism. Intensity of skin reaction in the form of oedema and erythema after intracutaneously administered codeine varied between the studied groups. The highest intensity was found in patients with irritable colon syndrome (ICS) who had intermittent diarrhoeas. The intensity of oedematous skin reaction after codeine in patients with ICS was correlated with the degree of irritability of the large bowel evaluated by the accepted score. The obtained results may be an indirect evidence of the participation of pseudoallergic reaction in the pathological mechanism of ICS in certain patients.
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PMID:[Hypersensitivity reactions in patients with irritable colon syndrome]. 803 Mar 24

Terminal ileal biopsies were prospectively obtained and stained specifically for mast cells in 20 patients with irritable bowel syndrome (IBS) and 15 controls. The number of terminal ileal mast cells per high powered field (MC/HPF) (mean +/- SEM) was 23.3 +/- 3.1 for IBS and 6.8 +/- 1.1 for controls (P = 0.0001). The diarrhea IBS subgroup had the greatest number of MC/HPF. No correlation was found between terminal ileal mucosal mast cell counts (MMCC) and the number of Manning criteria present or the functional bowel disease score (r = 0.06 and r = -0.31, respectively). We conclude that terminal ileal MMCC are significantly elevated in a majority of patients with IBS. The mast cell may be responsible for the altered visceral perception found in the gastrointestinal tract in patients with IBS. The poor correlation of the MMCC to the clinical features of IBS may be the result of the dynamic state of the mast cell.
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PMID:Terminal ileal mucosal mast cells in irritable bowel syndrome. 835 68

To investigate whether the mast cells (MC) of the ileocecal junction (ICJ) is elevated in the irritable bowel syndrome (IBS) and the possible roles of the MC in IBS, the biopsies of ICJ were stained specifically by histochemistry for the MC in the IBS group (n = 20) and the normal group (n = 19). The structure relation between MC and nerves was studied through an electronic microscopy and an immunohistochemical method demonstrating neuronspecific enolase. The results demonstrated that the number of the MC of ICJ was significantly elevated in the IBS (P = 0.019) and that mast cells were close to nerves which were often unmyelinated nerves in lamina propria. The results indicate that the MC of ICJ may be responsible for the pathophysiology of the IBS. We conclude that the MC of ICJ may be a mediator between the gut and the nervous system in the IBS, and that the mast cell stabilizer or the antagonists of the mast cell products may have potential treatment effects on the IBS.
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PMID:[Mast cells of ileocecal junction in irritable bowel syndrome]. 1037 83

There have frequently been doubts as to the relevance of food allergy, in particular as far as the involvement of the intestinal tract is concerned. Several studies, however, have confirmed the existence of allergic reactions in the gut, with an estimated prevalence of about 1-2% in adults. Clinical symptoms are unspecific and include nausea, vomiting, abdominal pain, cramping and diarrhea. Intestinal mast cells, as well as intestinal eosinophils, have been shown to be involved in the pathogenesis of food-allergy-related enteropathy. In addition to classical IgE-dependent degranulation, further agonists have been demonstrated for mast cell activation, for example IL-4. The methods used to confirm the diagnosis of intestinal allergy are still insufficient. Until now, blinded oral challenge procedures with food antigens have been accepted as the 'gold standard' in diagnosing food allergy, although these tests have practical problems. Therefore, new test systems have been developed, such as endoscopic provocation tests, that may improve diagnostic procedures. Elimination diet still presents the main basis of therapy. Aspects to be focused on in the future are the role fo IgE-independent allergic mechanisms in intestinal allergy, the impact of cross-reactivity with other allergens and the relationship to other inflammatory bowel diseases such as Crohn's disease, ulcerative colitis, celiac disease and irritable bowel syndrome.
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PMID:Allergy and the gut. 1082 17

Mast cells (MC) release potent mediators which alter enteric nerve and smooth muscle function and may play a role in the pathogenesis of the irritable bowel syndrome (IBS). The aim of this study was to determine if MC were increased in the colon of IBS patients compared to controls. Biopsy specimens were obtained from the caecum, ascending colon, descending colon and rectum of 28 patients: 14 IBS (Rome criteria); seven normal; and seven inflammatory controls. Tissue was stained immunohistochemically using a monoclonal mouse antibody for human mast cell tryptase (AA1). Tissue area occupied by tryptase-positive MC (volume density of mast cells) was quantified by image analysis. The number of plasma cells, lymphocytes, eosinophils, neutrophils and macrophages were each graded semiquantitatively (0-4) in haematoxylin and eosin stained sections. Mast cell volume density was significantly (P < 0.05) higher in IBS (0.91 +/- 0.18; CI 0.79; 1.0) than normal controls (0.55 +/- 0.14; CI 0.40; 0.69) in the caecum but not at other sites. Apart from MC, there was no evidence of increased cellular infiltrate in the IBS group. MC were significantly increased in the caecum of IBS patients compared to controls. The multiple effects of the intestinal mast cell alone, or as a participant of a persistent inflammatory response, may be fundamental to the pathogenesis of IBS.
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PMID:Increased mast cells in the irritable bowel syndrome. 1101 45

Stressful life events are frequently associated with outward signs of irritable bowel syndrome (IBS). Increasing evidence suggests that acute and chronic stress stimuli implicate different physiological mechanisms and neuroendocrine responses. Therefore, we investigated the influence of acute and chronic stress on visceral nociception in female rats and the involvement of colonic mast cells in this effect. The effect of acute and chronic partial restraint stress (PRS) on visceral sensitivity to rectal distension (RD) was assessed by abdominal muscle electromyography. Colonic mast cell activation was determined by measuring histamine release after in vitro stimulation with substance P (SP) in colonic samples from rats experiencing RD vs. controls. Acute PRS significantly enhanced abdominal response to RD compared with sham PRS for all volumes of distension. In contrast, chronic PRS induced a hyperalgesic response for the highest volumes of distension (0.8 and 1.2 mL), but did not affect the number of abdominal contractions for the lowest volume (0.4 mL) compared with controls. Both acute and chronic PRS increased in vitro SP-induced histamine release without affecting mast cell numbers. RD induced similar in vitro histamine release from colonic samples from both acute and chronic PRS rats; this release, however, was significantly higher than that measured in sham-PRS rats. Acute and chronic PRS differently influence visceral sensitivity in response to RD in female rats. This difference, however, cannot be attributed to a different effect of either stress paradigm on mast cell histamine release.
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PMID:Acute and chronic stress differently affect visceral sensitivity to rectal distension in female rats. 1187 56

The involvement of mucosal mast cells (MMC) in the pathophysiology of irritable bowel syndrome (IBS) is still controversial. We aimed to re-evaluate the role of MMC in visceral hypersensitivity associated with IBS using a rat IBS model that develops the IBS symptom after a subsidence of acetic acid-induced colitis. No significant difference in the number of MMC was observed between normal rat colon and IBS rat colon. (61.7 +/- 2.9/mm(2) in normal vs. 88.7 +/- 13.3/mm(2) in IBS, p > 0.29). However, the degranulation rate of MMC was significantly higher in IBS rat colon (49.5 +/- 2.4% in normal vs. 68.8 +/- 3.4% in IBS, p < 0.05). Pretreatment of a mast cell stabilizer, doxantrazole (5 mg/kg, i.p.), reduced the degranulation rate of MMC and significantly attenuated visceral hypersensitivity to rectal distension in IBS rat, whereas it had no effect on the visceral sensory responses in normal rat. These results suggest that, although the number of MMC is not significantly changed in IBS rat colon, the higher degranulation rate of MMC is responsible for visceral hypersensitivity in this model IBS.
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PMID:Role of mucosal mast cells in visceral hypersensitivity in a rat model of irritable bowel syndrome. 1561 15


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