Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Antigenic challenge of jejunum from rats infected with Trichinella spiralis evokes a biphasic pattern of epithelial Cl- secretion, as measured in vitro by electrophysiological methods. Peaks of secretion occur at approximately 1.5 and approximately 5.0 min post-challenge. Challenge of jejunum from hosts passively immunized with serum containing anti-Trichinella anaphylactic antibody evokes the late phase but not the early phase of Cl- secretion. Since the early phase is mediated by 5-hydroxytryptamine and histamine from mast cells, we hypothesized that the failure to express that phase was due to a decrease in mast cell-derived mediators secondary to a deficiency in mucosal mast cell numbers. The hypothesis was tested by correlating mast cell numbers with patterns of antigen-induced Cl- secretion using several immunization regimes. Rats actively immunized by infection produced anti-Trichinella IgE and had a mucosal mastocytosis. Rats passively sensitized with serum containing anti-Trichinella IgE had normal numbers of mast cells in their mucosa. Inducing mastocytosis in rats, by infecting them with Nippostrongylus brasiliensis prior to passive sensitization with anti-Trichinella serum, primed for the expression of a biphasic Cl- secretory response upon subsequent challenge with Trichinella antigen. Rats actively sensitized by injection with Trichinella antigen elicited an IgE response without mastocytosis and expressed only the late phase of antigen-induced Cl- secretion. Results (i) support our hypothesis, (ii) emphasize the importance of the cellular state of the mucosa in the functional expression of local anaphylaxis; and (iii) provide a physiological explanation for the general failure of vaccination and passive sensitization to induce functional immunity equivalent to that induced by natural infection.
 ...
PMID:Simulation of parasite-induced gut hypersensitivity: implications for vaccination. 292 27

We examined contractility of longitudinal muscle strips of jejunum from control rats and rats infected 34-85 days previously with Trichinella spiralis. Antigen prepared from T. spiralis larvae contracted muscle from previously infected but not control rats. Contraction was specific for the sensitizing agent because antigen from Nippostrongylus brasiliensis did not induce contraction. Contraction was resistant to atropine or tetrodotoxin but was inhibited by the 5-hydroxytryptamine (5-HT) antagonist cyproheptadine and by 5-HT desensitization. Neither histamine antagonists, diphenhydramine (H1-receptor antagonist) or ranitidine (H2-receptor antagonist), nor indomethacin, a prostaglandin synthase inhibitor, influenced the antigen response. In Trichinella-infected rats there was a significant increase in mast cell number in the muscle layers, and the contraction induced by T. spiralis antigen was inhibited by the mast cell stabilizer doxantrazole. In addition, anti-rat immunoglobulin E serum, compound 48/80, and concanavalin A each contracted muscles from rats previously infected with T. spiralis. These results are consistent with the hypothesis that T. spiralis infection leads to mast cell proliferation in the muscle layers and that subsequent exposure to antigen results in mast cell degranulation, 5-HT release, and contraction of smooth muscle.
 ...
PMID:Antigen-induced contraction of jejunal smooth muscle in the sensitized rat. 320 67

Histochemical and ultrastructural properties of endoneurial mast cells of the normal and histamine liberator Compound 48/80 (48/80)--injected musk shrew, Suncus murinus (Suncus) were examined by light and electron microscopies. It was observed that the normal mast cells contained numerous cytoplasmic granules, with dense and irregular dense cores, covered at times with slender microvilli. The cells were diffusely located within the endoneurial sheath of the peripheral nerve fibers and in the intercellular spaces of the spinal ganglion cells. Histochemically, histamine, 5-hydroxytryptamine and heparin were observed in mast cell granules. Biochemical analysis also indicated a relatively high content of histamine in the suncus peripheral nerve. A single intradural-injection of 48/80 resulted in the degranulation of endoneurial mast cells and revealed peculiar axoplasmic changes make up of neurofilament-mitochondrial complexes in the peripheral nerve fibers. No remarkable histochemical and ultrastructural differences were observed between the endoneurial mast cells and the connective tissue mast cells in the suncus. The significance of these findings is discussed with regard to previous studies of the endoneurial mast cells in other laboratory animals.
 ...
PMID:An electron microscopical observation of the endoneurial mast cells of the laboratory musk shrew: Suncus murinus). 340 Aug 80

The effects of histamine, 5-hydroxytryptamine (5-HT) and prostaglandin E2 (PGE2) on plasma protein extravasation in the rat subcutaneous air-pouch have been studied. Both histamine and 5-HT produced increases in plasma protein extravasation which were inhibited by specific receptor antagonists. Plasma protein extravasation induced by PGE2 was partially inhibited by either a 5-HT receptor antagonist (methysergide) or by a combination of H1 and H2 receptor antagonists (mepyramine and cimetidine). A combination of all three antagonists further reduced plasma protein extravasation. These results suggest that PGE2 increases vascular permeability indirectly via the degranulation of mast cells. This supposition was confirmed by histological evidence of extensive mast cell degranulation following the injection of PGE2 but not following histamine, 5-HT or saline injection. Using a technique of vascular labelling, following the intravenous injection of Monastral blue dye, plasma extravasation induced by histamine, 5-HT or PGE2 was observed to be restricted to post-capillary venules and was not observed in arterioles or capillaries. Electron microscopic examination of the tissue revealed the presence of monastral blue particles trapped between endothelial cells. These findings suggest that the microcirculation of the rat subcutaneous air-pouch behaves in an analogous manner to that of other tissues.
 ...
PMID:A pharmacological and histological examination of the microcirculation of the rat subcutaneous air-pouch: microcirculation of the rat air-pouch. 343 17

The ability of the venoms of Atrax infensus and two other funnel-web spider species to induce oedema in rats was investigated and it was found that all Atrax venoms tested caused strong Evans blue leakage from adjacent blood vessels when injected subcutaneously. This dye leakage did not diminish significantly either when the neurotoxin in the venom was first neutralized by pre-mixing with a rat serum protein preparation or when the sensory nerves supplying an area of skin were severed 4 days prior to its envenomation. The pattern and speed of Evans blue extravasation caused by female A. infensus venom resembled that for histamine and for 5-hydroxytryptamine, and pretreatment with an antihistamine-antiserotonin mixture caused essentially complete blockade of the oedematogenic action of this venom, although neither inhibitory drug was very effective when used individually. It was concluded that this venom induces local oedema in rats mainly by causing mast cell degranulation. In confirmation of this, the mast cells in the rat skull periosteal membranes were found to be extensively degranulated by exposure to the venom. Surprisingly, whole-rat envenomation, using very large doses of venom, produced little dye leakage even though obvious symptoms of neurotoxic action were observed.
 ...
PMID:Some studies of the oedematogenic action of the venom of funnel-web spiders (Atrax species). 357 39

This study was designed to investigate the effect of middle-wave ultraviolet (UVB) radiation on mast cell functions using mouse ear skin as an in vivo model. Groups of UVB-irradiated BALB/c mice were given an intradermal injection of the mast cell degranulator compound 48/80 into ears at various time intervals (30 min-7 days) after a single exposure to a bank of fluorescent sunlamp tubes (10-100 mJ/cm2). Both the compound-evoked ear swelling response (ESR) and mast cell degranulation were significantly suppressed by preexposure to UVB (25-100 mJ/cm2) after 0 (30 min) to 3 days postirradiation, with a subsequent recovery by day 7. No such effects were observed in mice irradiated with 10 mJ/cm2. The ESR induced by 5-hydroxytryptamine was not significantly affected by UVB radiation during the experimental period. While within this dose range UV radiation itself caused neither loss of mast cell counts nor a measurable degree of degranulation in ear skin, exposure to larger amounts of UV energy (200-500 mJ/cm2) produced tremendous ear swelling with histologic features of mast cell degranulation in an early phase of inflammation. The results suggest that UVB radiation exerts a dual effect on mast cells and that administration of smaller amounts of UVB may alter the mast cell/vasoactive amine system, suppressing ear swelling in response to the degranulator. Vascular reactivities to vasoactive amines were not affected by UVB irradiation.
 ...
PMID:Ultraviolet-B radiation suppresses mast cell degranulation induced by compound 48/80. 378 60

This paper reports an attempt to measure the normal growth of connective tissue mast cells in rats aged 6 to 24 weeks. We used peritoneal mast cells as a model, and calculated the total mast cell mass and the mass of its components from total peritoneal mast cell numbers and their content of protein, heparin, histamine and 5-hydroxytryptamine (5-HT). The growth process was analysed with the aid of allometric, log-log plots of mast cell quantities versus body weight and linear regression, in order to facilitate comparisons with other systems, notably the lymphoid apparatus. We found that the growth of peritoneal mast cells conformed to the allometric principle (r = 0.91 to 0.93). There were no deviations from linearity or changes in the slope (growth rate constant, k) of the allometric lines within the studied growth interval. K ranged from 1.3 to 1.7, indicating that the mast cell mass and its different components grew at a faster rate than the body as a whole, typical of a late maturing cell system. The mode of growth of the peritoneal mast cells is thus distinctly different from that of the lymphoid system, and neither thymus involution nor sexual maturation appears to influence the growth of these cells.
 ...
PMID:Allometric growth of the rat peritoneal mast cell mass and of the granular constituents: heparin, histamine and 5-hydroxytryptamine. 383 13

We determined the serotonin (5-hydroxytryptamine, 5HT) content of growth factor dependent mouse mast cell lines or clones, and measured their ability to synthesize and store 3H-5HT from exogenous 5-hydroxy-[G-3H]-tryptophan (3H-5HTP) in vitro. Mast cells grown in vitro synthesized 3H-5HT from 3H-5HTP at rates equal to or greater than those of peritoneal mast cells freshly isolated from normal mice. Furthermore, under usual conditions of culture, mast cell lines or clones contained more 5HT than freshly isolated peritoneal mast cells.
 ...
PMID:Cloned mouse mast cells and normal mouse peritoneal mast cells. Determination of serotonin content and ability to synthesize serotonin in vitro. 387 66

In order to see whether 8-methoxypsoralen (8-MOP) plus long-wave ultraviolet (UVA) radiation (PUVA) has an influence on immediate-type skin reactions, we have undertaken an animal study. Ears of mice were treated with a 0.5% 8-MOP solution topically plus UVA radiation (1.5-2.5 J/cm2). After PUVA radiation, skin responses to intradermal injection with mast cell liberators, including compound 48/80 (2.5 mg/ml, 10 microliter) and concanavalin A (Con-A) (2.0 mg/ml), or with a mixture of 5-hydroxytryptamine (5-HT) and histamine as vasodilator (1.0 mg/ml and 50 mM, respectively) were examined with time (2 h-14 days). At each time point, an ear swelling response (ESR) was measured with a dial thickness gauge. The rate of mast cell degranulation and mast cell numbers were assessed by light microscopy using toluidine blue-stained semithin (1 micron) sections. ESR induced by compound 48/80 or Con-A was significantly suppressed dose-dependently (greater than 42% inhibition) by PUVA between 2 h-3 days postirradiation as compared with that in nonirradiated control mice, and the value returned to normal levels by 7-14 days. Compound 48/80- or Con-A-induced mast cell degranulation (%) was remarkably decreased between 2 h-3 days (greater than 48% inhibition) in accordance with the suppression in ESR and it was restored to the rates in nonirradiated controls by 7-14 days. Neither ESR nor percent degranulation was affected by UVA radiation only (less than 3.5 J/cm2) or application of 8-MOP only. 5-HT plus histamine-mediated ESR was not altered at all by PUVA throughout the experimental period. Since PUVA radiation itself at given doses did not produce measurable ESR, mast cell degranulation, or a reduction in mast cell numbers, and since PUVA did not affect a normal vascular response to vasodilator, it seemed that decreased skin reactivity to mast cell degranulators by PUVA might be due to a PUVA-induced noncytolytic alteration in mast cell release mechanisms.
 ...
PMID:The effect of 8-methoxypsoralen plus long-wave ultraviolet (PUVA) radiation on mast cells: PUVA suppresses degranulation of mouse skin mast cells induced by compound 48/80 or concanavalin A. 387 15

The allergenicity of bovine beta-lactoglobulin (beta-LG) in rats was investigated by measurement of both mast cell-bound and circulating IgE antibody produced in response to immunisation with this cow's milk constituent. The responsiveness of the animals' peritoneal mast cells to in vitro challenge with beta-LG was determined by measurement of release of radiolabelled 5-hydroxytryptamine. Using aluminium hydroxide gel as adjuvant, the responsiveness of mast cells to beta-LG was transient, peaking at 21 days after immunisation. The optimal dose of injected beta-LG was 100 micrograms. Circulating IgE antibody to beta-LG, measured by ELISA, was also detected transiently during the 3rd week post-immunisation.
 ...
PMID:Studies on beta-lactoglobulin as an experimental allergen in rats. 396 36


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>