Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inflammatory or allergic conditions, as well as situations where healing and repair processes occur, are characterized by the presence of increased numbers of mast cells. Previous work on the effect of neuropeptides on mast cell mediator release showed that only substance P caused such release from intestinal mucosal mast cells [Shanahan, F., Denburg, J. A., Fox, J., Bienenstock, J. & Befus, A. D. (1985) J. Immunol. 135, 1331-1337]. Accordingly, we investigated the microanatomical relationship between mast cells and enteric nerves in normal rat intestine and parasite-infected rat intestine, in which mucosal mast cell hyperplasia occurs. Combined immunohistochemistry for neuron-specific enolase and staining with alcian blue at pH 0.5 was employed on paraffin-embedded sections of normal and Nippostrongylus brasiliensis-infected rat jejunum. Sixty-seven percent of intestinal mucosal mast cells were touching subepithelial nerves, and an additional 20% were within 2 micron of nerves. Assessment of the proportion of the lamina propria occupied by mast cells (12.5%), the average mast cell area (121 +/- 28 microns 2), and the density of enteric nerves (one per 788 +/- 151 microns 2) suggested that the association was 5 times greater than would be expected by chance alone (P less than 0.0001). In consecutive sections, the nerves in contact with mast cells were also shown to contain substance P and/or calcitonin-gene-related peptide. Electron microscopy confirmed this association: 8% of the mast cells in infected rats exhibited membrane-membrane contact with unmyelinated axons containing 70- to 170-nm dense-core vesicles, and an additional 31% were situated less than 250 nm from nerves. Other mast cells appeared to embrace nerve bundles through the projection of lamellopodia. These data provide systematic quantitative evidence that a structural foundation for communication between the immune and nervous systems exists in the rat gastrointestinal tract.
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PMID:Intestinal mucosal mast cells in normal and nematode-infected rat intestines are in intimate contact with peptidergic nerves. 243 89

Our studies have clearly shown that neuropeptides have a profound effect on immunoglobulin synthesis both in vivo and in vitro. The effects varied according to the neuropeptide added or the tissue from which the lymphocytes were obtained. Substance P caused the most pronounced enhancement of both functions, especially in Peyer's patch cells, where it selectively increased IgA synthesis. Somatostatin was inhibitory, and the effect of vasoactive intestinal peptide varied according to the source of the cells. We have previously shown that neuropeptides also cause mast cell secretion and that only substance P was effective in this regard on intestinal mucosal mast cells. Therefore, we looked for microanatomic relationships between peptidergic nerves and immune effector cells. Mast cells appear to have structural associations with neuropeptides-containing nerves in the intestine. Nerve growth factor, known to promote the growth of sensory afferent and sympathetic nerves, has significant direct effects on mast cells. In vitro, this substance caused enhanced antigen mediated histamine release and, in vivo, extensive mast cell hyperplasia. Also, in humans, we were able to produce increased numbers of mast cell/basophil colonies from peripheral blood in the presence of nerve growth factor.
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PMID:Neuropeptides and immunity. 244 42

To study the nature and extent of mast cell heterogeneity within a single species, we have developed methodologies to isolate rat lung mast cells (LMC) and have compared these to peritoneal mast cells (PMC) and intestinal mucosal mast cells (IMMC). In normal and athymic nude (rnu/rnu) rats, a single intratracheal administration of bleomycin (5 U/kg) leads to pulmonary fibrosis accompanied by parenchymal hyperplasia of mast cells that are histochemically like PMC rather than IMMC. Using collagenase digestion of fibrotic rat lungs (30-80 days after bleomycin treatment), we recovered an average of 58.1 x 10(6) viable cells per rat, containing 2.5% mast cells. Control experiments in which PMC were subjected to the isolation procedure used for LMC showed that there was no qualitative effect on PMC, but that a reduction of 26-60% in responsiveness to secretagogues occurred. Isolated LMC secreted histamine in response to 48/80, A23187, substance P, VIP and somatostatin and bradykinin, but at lower levels than PMC. The anti-allergic compound theophylline, which does not inhibit antigen-induced histamine secretion by IMMC, was effective against both LMC and PMC. Taken together, the thymus independence of pulmonary mast cell hyperplasia, the histochemical characteristics and the responsiveness to secretagogues and anti-allergic compounds indicate that the majority of dispersed LMC are similar to PMC rather than to IMMC. Whether LMC should be considered analogous to PMC or, because of their size, histamine content and responsiveness to many secretagogues, intermediate between PMC and IMMC, remains to be determined through additional studies.
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PMID:Isolation and characterization of lung mast cells from rats with bleomycin-induced pulmonary fibrosis. 246 79

In 16 consecutive patients with systemic mastocytosis, we prospectively evaluated a variety of gastrointestinal functions and examined how they relate to the occurrence of gastrointestinal symptoms. Nine patients had either a duodenal ulcer or duodenitis. Hypersecretion of gastric acid was present in 6 patients, and in these patients the mean basal acid output was 20.7 +/- 4.1 mEq/h (range 14-39 mEq/h). Impaired small intestinal absorption occurred in 5 patients, although this was usually mild. The mean fractional emptying rate of liquids for all patients (14.7% +/- 2.3% per minute) did not differ from that for controls (10.7% +/- 0.6% per minute). Mean mouth-to-cecum transit time measured by breath hydrogen testing was the same among patients (87.7 +/- 6.7 min) and controls (86.7 +/- 8.0 min). Plasma histamine concentrations were increased in all patients (mean 1886 pg/ml, range 480-7450) and correlated with the basal acid output (r = 0.64, p less than 0.02) but not maximal acid output or the presence or absence of pain or diarrhea. Mean fasting plasma concentrations of motilin, substance P, and neurotensin from 6 patients did not differ significantly from controls, whereas gastrin and vasoactive intestinal peptide were significantly less than in controls (p less than 0.01). Gastrointestinal symptoms, consisting of abdominal pain or diarrhea, occurred in 80% of patients. Abdominal pain classified as dyspeptic was usually associated with acid-peptic disease of the duodenum and hypersecretion of gastric acid, whereas abdominal pain of a nondyspeptic character was not. Only in those cases of diarrhea consisting of greater than 200 g stool/day was gastric acid hypersecretion frequently found. Neither fecal urgency nor nondyspeptic pain could be accounted for by alterations of gastrointestinal transit. These results demonstrate that gastrointestinal symptoms, peptic disease, and mild malabsorption are much more common than described previously in patients with systemic mastocytosis. Furthermore, the results provide no evidence for the contention that altered gastrointestinal transit is involved in the pathogenesis of these symptoms.
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PMID:Gastrointestinal dysfunction in systemic mastocytosis. A prospective study. 339 14

Substance P (SP) stimulates human skin and rodent mast cells. Since neuropeptide-mediated reflexes may be important in asthma, the ability of SP to stimulate human mast cells obtained at bronchoalveolar lavage (BAL) was examined. Routine BAL (n = 22) samples were obtained and histamine release experiments performed in a standard manner. Spontaneous histamine release was bimodally distributed (Group A, high spontaneous release/Group B, normal spontaneous release). Further, Group A had significantly elevated corrected SP-induced histamine release compared to Group B but the corrected calcium ionophore A23187-induced responses were similar. No differences were found in clinical history, age, lavage return or total cell numbers between groups. However, differential cell counts revealed significantly elevated mast cell numbers in Group A providing further evidence for altered mast cell responsivity associated with mast cell hyperplasia. In asthma, BAL mast cells have increased spontaneous and stimulated secretory responses; thus, in asthma SP may also stimulate pulmonary mast cells.
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PMID:Differential reactivity of human bronchoalveolar lavage mast cells to substance P. 752 45

The epithelium of the gastrointestinal tract is continuously exposed to the external environment containing food antigens, microbes and other pathogens. Immunologic and nonimmunologic mechanisms contribute to the neutralization and elimination of these foreign antigens. The immune system of the intestine is the most extensive in the organism and involves diffuse populations of immune cells, lymphoid aggregates and intraepithelial lymphocytes. On the other hand, the functions of the digestive tract contribute to the overall host defense (mucus secretion, gastric acid secretion, water and electrolyte secretion and peristaltism). These functions are regulated by intrinsic and extrinsic nervous systems. It is currently recognized that the physiological and pathological responses of the intestine require an integrate neuroimmune network. Such neuroimmune regulation is based on anatomical and biochemical supports. Indeed, there are membrane-to-membrane contacts between axonal varicosities and the immune cells. Specific receptors for neurotransmitters such as substance P, vasoactive intestinal polypeptide and somatostatin have been identified in many immune cells. Nerve profile change has been described under pathological conditions such as parasitic infections and acute phase of inflammation. In addition to supporting the growth and survival of several populations of nerves the classical nerve growth factor (NGF) has been shown to affect an immune cell population by inducing mast cell hyperplasia. Furthermore the NGF can induce mast cell degranulation, acting directly on mast cell membrane NGF receptors or indirectly by NGF-mediated release of substance P by peripheral extrinsic or intrinsic nerves. Moreover, non-immune cells such as epithelial and smooth muscle cells can produce immunologic messengers under pathological conditions such as infectious diseases or inflammation. Besides the local regulation of gut functions, neuroimmune control can be exerted at extra-intestinal sites. During physiological and pathological conditions, gastrointestinal secretions and motor events are strongly regulated by the central nervous system. Moreover, infectious agents can induce cytokine and particularly interleukin-1 release by the brain astrocytes and microglial cells which have been shown to play a pivotal role in fever induction and modifications of the gastrointestinal functions. Visceral afferent fibers play a pivotal role in 'cross-communication' between central sites and immune response. Recent studies evoke, more specifically, the role of vagus as a key modulatory participant in the close relationship between the extraintestinal nerves and the immune system. Future work in this field will clarify the role of the different participants in the intimate communication between the gastrointestinal tract, immune system and central nervous system.
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PMID:Integrative neuroimmunology of the digestive tract. 882 13

Nippostrongylus brasiliensis infection induces jejunal mastocytosis associated with enteric nerve remodelling in rats. The aim of this study was to evaluate the intestinal motility responses to meals and to neurotransmitters involved in the control of gut motility (acetylcholine (carbachol), substance P and neurokinin A) in both control and N. brasiliensis-infected rats 30 days post-infection. All rats were equipped with NiCr electrodes in the jejunum to record myoelectrical activity. The duration of disruption of the jejunal migrating myoelectrical complexes (MMC) induced by the different stimuli was determined. Meal ingestion and substance P administration disrupted the MMC pattern for similar durations in the two groups. Carbachol and neurokinin A induced a significantly longer MMC disruption in post-infected rats than in controls (125 +/- 8.3 vs. 70 +/- 6 min for carbachol 100 microg kg-1 and 51 +/- 4 vs. 40 +/- 2 for neurokinin A 50 microg kg-1). The enhanced motor response in postinfected rats was reduced by previous mast cell stabilization with ketotifen or mast cell degranulation with compound BrX 537 A. In conclusion, the increased intestinal motor reactivity to carbachol and neurokinin A in post-N. brasiliensis-infected rats depends upon intestinal mast cell hyperplasia and degranulation.
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PMID:Alterations of intestinal motor responses to various stimuli after Nippostrongylus brasiliensis infection in rats: role of mast cells. 1086 17

The vanilloid receptor subtype 1 (VR1)/(TRPV1), binding capsaicin, is a non-selective cation channel that recently has been shown in human keratinocytes in vitro and in vivo. However, a description of VR1 localization in other cutaneous compartments in particular cutaneous nerve fibers is still lacking. We therefore investigated VR1 immunoreactivity as well as mRNA and protein expression in a series (n = 26) of normal (n = 7), diseased (n = 13) [prurigo nodularis (PN) (n = 10), generalized pruritus (n = 1), and mastocytosis (n = 2)], and capsaicin-treated human skin (n = 6). VR1 immunoreactivity could be observed in cutaneous sensory nerve fibers, mast cells, epidermal keratinocytes, dermal blood vessels, the inner root sheet and the infundibulum of hair follicles, differentiated sebocytes, sweat gland ducts, and the secretory portion of eccrine sweat glands. Upon reverse transcriptase-polymerase chain reaction and Western blot analysis, VR1 was detected in mast cells and keratinocytes from human skin. In pruritic skin of PN, VR1 expression was highly increased in epidermal keratinocytes and nerve fibers, which was normalized after capsaicin application. During capsaicin therapy, a reduction of neuropeptides (substance P, calcitonin gene-related peptide) was observed. After cessation of capsaicin therapy, neuropeptides re-accumulated in skin nerves. In conclusion, VR1 is widely distributed in the skin, suggesting a major role for this receptor, e.g. in nociception and neurogenic inflammation.
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PMID:Expression of vanilloid receptor subtype 1 in cutaneous sensory nerve fibers, mast cells, and epithelial cells of appendage structures. 1498 52

Upregulation of CGRP-immunoreactive (IR) primary afferent nerve fibers accompanied by mastocytosis is characteristic for the Schistosoma mansoni-infected murine ileum. These mucosal mast cells (MMC) and CGRP-IR fibers, which originate from dorsal root (DRG) and nodose ganglia, are found in close apposition. We examined interactions between primary cultured MMC and CGRP-IR DRG neurons in vitro by confocal recording of intracellular Ca(2+) concentration ([Ca(2+)](i)). The degranulatory EC(50) for the mast cell secretagogue compound 48/80 (C48/80; 10 microg/ml) and the neuropeptides CGRP (2.10(-8) M) and substance P (SP; 3.10(-8) M) were determined by measurement of extracellular release of the granule chymase, mouse mast cell protease-1. Application of C48/80 (10 microg/ml) and CGRP and SP (both 10(-7) M) to Fluo-4-loaded MMC induced a transient rise in [Ca(2+)](i) after a lag time, indicative of mast cell degranulation and/or secretion. The CGRP response could be completely blocked by pertussis toxin (2 microg/ml), indicating involvement of G(i) proteins. Application of MMC juice, obtained by C48/80 degranulation of MMC, to Fluo-4-loaded DRG neurons induced in all neurons a rise in [Ca(2+)](i), indicative of activation. Degranulation of MMC by C48/80 in culture dishes containing Fluo-4-loaded DRG neurons also caused activation of the DRG neurons. In conclusion, these results demonstrate a bidirectional cross-talk between cultured MMC and CGRP-IR DRG neurons in vitro. This indicates that such a communication may be the functional relevance for the close apposition between MMC and CGRP-IR nerve fibers in vivo.
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PMID:In vitro activation of murine DRG neurons by CGRP-mediated mucosal mast cell degranulation. 1501 15

Each year, millions of people worldwide are treated for primary or recurrent pelvic malignancies, involving radiotherapy in almost 50% of cases. Delayed development of visceral complications after radiotherapy is recognized in cancer survivors. Therapeutic doses of radiation may lead to the damage of healthy tissue around the tumor and abdominal pain. Because of the lack of experimental models, the underlying mechanisms of radiation-induced long-lasting visceral pain are still unknown. This makes managing radiation-induced pain difficult, and the therapeutic strategies proposed are mostly inefficient. The aim of our study was to develop an animal model of radiation-induced visceral hypersensitivity to (1) analyze some cellular and molecular mechanisms involved and (2) to test a therapeutic strategy using mesenchymal stromal cells (MSCs). Using a single 27-Grays colorectal irradiation in rats, we showed that such exposure induces a persistent visceral allodynia that is associated with an increased spinal sensitization (enhanced p-ERK neurons), colonic neuroplasticity (as increased density of substance P nerve fibers), and colonic mast cell hyperplasia and hypertrophy. Mast cell stabilization by ketotifen provided evidence of their functional involvement in radiation-induced allodynia. Finally, intravenous injection of 1.5 million MSCs, 4 weeks after irradiation, induced a time-dependent reversion of the visceral allodynia and a reduction of the number of anatomical interactions between mast cells and PGP9.5+ nerve fibers. Moreover, unlike ketotifen, MSC treatment has the key advantage to limit radiation-induced colonic ulceration. This work provides new insights into the potential use of MSCs as cellular therapy in the treatment of pelvic radiation disease.
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PMID:Persistent visceral allodynia in rats exposed to colorectal irradiation is reversed by mesenchymal stromal cell treatment. 2588 64


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