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

Cytofluorometric quantitation of 5-hydroxytryptamine (5-HT) and heparin in individual mast cell granules is described. The technique is based on micromanipulation of intact mast cells reacted with formaldehyde or stained with Berberine sulfate and the use of a cytofluorometer equipped with a sensitive peak detecting device. The quantities of 5-HT and heparin contained in mast cell granules which are of the order of 10(-16) and 10(-13) g, respectively were expressed as relative fluorescence guanta. The results of measurements on representative samples of mast cell granules indicate that all granules contain heparin as well as 5-HT, and that there are large variations in both 5-HT and heparin content within the granule populations of individual cells. A dose dependent increase in 5-HT content in both cells and individual mast cell granules occurred 24 hr after the injection of 10--50 mg L-5-hydroxytryptophan/kg intraperitoneally. There was no evidence for an increase in the heparin content of granules or cells, indicating that a new synthesis of granular macromolecules is not required for the 5-HT uptake. The results further suggest that 5-HT may be stored initially in a cytoplasmic extragranular pool and then taken up in the mast cell granules.
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PMID:Cytofluorometric quantitation of 5-hydroxytryptamine and heparin in individual mast cell granules. 30 56

The mast cell population is heterogeneous concerning its amine precursor and amine uptake. The immature cells incorporate amine precursors, but in more advanced stages of their maturation they take up only 5-HTP. The mature cells do not take up precursors only 5-HT. The thyroid gland and heart muscle mast cells take up the highest amount of 5-HT; this may be related with some specific function of the mast cells in these two organs. Neither of the mast cells would take up histamine, the compound is synthetised by the cells.
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PMID:Biogenic amine and amine precursor uptake by mast cells. 30 84

Uptake and turnover of 5-hydroxytryptamine (5-HT) after the administration of 5-hydroxytryptophan (5-HTP) has been studied in rat peritoneal mast cells using radiochemical and quantitative cytofluorometric methods. There was a close agreement between the results obtained with the two methods. The extreme sensitivity of the cytofluorometric method was indicated by the fact that 0.2 pg 5-HT contained in mast cells from control rats could be readily quantitated. The cytofluorometric analysis demonstrated a large variation in 5-HT content of individual mast cells within the mast cell populations. The storage capacity for 5-HT greatly exceeded the amount found in normal mast cells. Intraperitoncally injected 5-HTP was rapidly taken up and eliminated from the mast cells within 12 hr, while 5-HT, probably derived from intracellular decarboxylation of 5-HTP, was retained in the cells and slowly eliminated. The elimination of 5-HT followed an exponential course and the half-life was found to be about 10 days. The results indicate that the turnover of 5-HT is much slower in mast cells than in other cells which normally store 5-HT.
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PMID:A cytofluorometric and radiochemical analysis of the uptake and turnover of 5-hydroxytryptamine in mast cells. 107 28

The biogenic amines and heparin of rat peritoneal mast cells were labelled in vivo by the injection of amine precursors (3H-histidine and 3H-5-hydroxytryptophan) and 35S-sodium sulfate. Uptake of label was rapid, probably reflecting the synthesis of new granule material, but the elimination was slow. Half-lives of radiolabelled histamine (23 days) and 5-hydroxytryptamine (5-HT; 25 days) did not differ statistically from that of heparin (35 days). The slow elimination rates suggest that mast cell secretion is of little biological significance under normal conditions but are well compatible with the idea that mast cell function is related to secretion evoked by appropriate immunological stimuli. It further permitted an analysis of the amine storage by repeated injections of unlabelled 5-HT. A 15-fold increase in 5-HT content was obtained while the total amine content remained constant. The uptake of 5-HT was balanced by a reduction of histamine in a molar 1:1 ratio. A displacement of histamine by 5-HT was further indicated by increased elimination rate of radiolabelled histamine in response to 5-HT injections. The results support previous binding studies in vitro and indicate that histamine and 5-HT are bound to identical storage sites in the mast cell granules.
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PMID:Storage and turnover of histamine, 5-hydroxytryptamine and heparin in rat peritoneal mast cells in vivo. 682 30

For individual mast cells, relationships between their dry mass and their content of heparin and 5-hydroxytryptamine (5-HT) were studied. This was achieved by measuring these parameters successively on identical cells, by means of quantitative cytochemical techniques. The peritoneal mast cells have a very long life span and a slow turnover of granule components. Increase of the dry weight of the cells may therefore be taken as an expression of cellular growth. Mast cell populations from younger and older animals were analysed in an attempt to evaluate the influence of cell-aging and animal-aging on the growth of the mast cells. The analysis was based on allometric (log-log) plots and linear regressions. Within the cell populations there were strong mutual correlations between the cell parameters studied, without any obvious deviations from linearity. However, the slopes of the allometric lines indicated a somewhat different mode of growth for mast cell from younger and older animals. The capacity of the mast cells to accumulate 5-HT after a single injection of its precursor, 5-hydroxytryptophan, was used as a functional test. In relation to the cell weight, the induced increase of 5-HT was greater for lighter than for heavier mast cells. This difference between light and heavy mast cells was greater for cells from younger than from older animals. These differences in growth and functional properties between mast cells from younger and older animals were interpreted as an effect of the animals rather than of aging of the cells.
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PMID:A quantitative cytochemical study of the growth of individual mast cells. 696 55

A feeder layer independent long-term in vitro culture system for murine mast cells is described. Concanavalin A-activated murine splenic leukocyte-conditioned medium, prepared under conditions optimal for T cell growth factor production, has been found also to contain a growth-promotion activity for murine mast cells identified by their morphology, characteristic ultrastructure of the granules, positive reactions with toluidine blue and alcian blue, presence of receptors for IgG and IgE, as well as presence of histamine, serotonin, L-Dopa, 5-hydroxytryptophan, and sulfated products within the cytoplasm. After 2 to 3 wk of culture in the presence of the conditioned medium, mast cell lines were established from various sources initially devoid of matured mast cells. Such sources included spleen and bone marrow of athymic nude mice, long-term cultured marrow cells as well as T cell-depleted normal marrow. Cultured mast cells are absolutely dependent upon the conditioned medium-derived growth factor(s) for growth and viability. Death ensues within 24 hr in the absence of the factor(s). Established mast cell lines have been maintained in exponential growth for over 1 yr by passaging in the conditioned medium every 3 to 7 days.
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PMID:Long-term in vitro culture of murine mast cells. I. Description of a growth factor-dependent culture technique. 701 32

Rabbit or rat isolated tracheae were incubated in vitro, and the release of 5-hydroxytryptamine (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) was determined by HPLC with electrochemical detection. Release of 5-HT from rabbit tracheae could be evoked by the calcium ionophore A 23187 and, in a calcium-dependent manner, by depolarizing concentrations of potassium (45 mmol/l), but not by the mast cell degranulating drug compound 48/80. High potassium- and A 23187-evoked release of 5-HT was markedly higher from tracheae of newborn compared to adult rabbits. In rabbit tracheae, mechanical removal of the mucosa resulted in 80-90% reduction in tissue 5-HT and in a similar reduction in high potassium-evoked 5-HT release. 5-Hydroxytryptophan, but not tryptophan, caused a marked increase in the spontaneous outflow of 5-HT and 5-HIAA from tracheae of newborn rabbits, and the effect on 5-HT, but not that on 5-HIAA, required an intact mucosa. Furthermore, treatment with 5-hydroxytryptophan caused an increase in tissue 5-HT and 5-HIAA, and these effects required an intact mucosa. In tracheae of adult rabbits 5-hydroxytryptophan caused similar, although less profound, effects. Adrenaline (1 micromol/1) enhanced the release of 5-HT from newborn rabbit tracheae, and this effect was inhibited by 1 micro mol/l phentolamine or 1 micromol/1 prazosin, but not affected by 100 nmol/1 propranolol. In rat tracheae, compound 48/80 evoked a large release of 5-HT, whereas depolarizing concentrations of potassium (45 mmol/1) had only a very minor effect. In rat tracheae, 5-hydroxytryptophan had small effects on the outflow and tissue contents of 5-HT and 5-HIAA in comparison to the effects on rabbit tracheae; and removal of the mucosa resulted in only a minor reduction in tissue 5-HT. In conclusion, neuroendocrine epithelial (NEE) cells and mast cells are the major source of 5-HT in tracheae of the rabbit and rat, respectively. Isolated tracheae of newborn rabbits appear to be a useful model to study 5-HT secretion from NEE cells. 5-HT secretion from NEE cells is activated by a rise in intracellular calcium, and calcium influx through voltage-regulated channels appears to be one activating pathway. 5-HT secretion from NEE cells can be stimulated via alpha-adrenoceptors.
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PMID:Characterization of 5-hydroxytryptamine release from isolated rabbit and rat trachea: the role of neuroendocrine epithelia cells and mast cells. 875 Sep 17

Visceral hypersensitivity is a common feature of functional bowel disorders, where an increased number of mast cells have often been described. Thus, we investigated the effect of an experimental mast cell degranulation induced by BrX-537A on somatic (tail heating) and visceral (rectal distension) sensitivity in rats and the involvement of histamine and/or serotonin on this last response. After BrX-537A administration, the latency of tail withdrawal reflex was shortened within the 2- to 8-hr period. Moreover, BrX-537A reduced the distension volume threshold from 0.8 ml to 0.4 ml inducing allodynia, from 6 to 12 hr after its administration. This effect was suppressed by doxantrazole (mast cell stabilizing agent) and WAY 100635 (5-HT1A receptor antagonist), and reproduced by 5-HTP (5-HT precursor) and 8-OH-DPAT (5-HT1A receptor agonist). However, neither granisetron (5-HT3 receptor antagonist) nor H1, H2, or H3 histamine receptor antagonists modified the BrX-537A-induced allodynia. Consequently, mast cell degranulation initiates a delayed somatic and visceral allodynia, with the participation of serotonin, through 5-HT1A receptor activation, on the visceral response.
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PMID:Mast cell degranulation induces delayed rectal allodynia in rats: role of histamine and 5-HT. 955 27

The radiation induced products of tryptophan (TRP) were determined in gamma-irradiated egg white, chicken meat and shrimps using RP-HPLC and electrochemical detection. A two-step hydrolysis with proteinase K and carboxypeptidase A was developed to release the radiation products from egg white and chicken meat and with proteinase K and pronase E from shrimps. The four hydroxytryptophan isomers (OH-Trp) were identified and quantified as radiation products in all samples. The amounts ranged between 0.02 and 1.97 mg/kg protein. A significant difference between irradiated and unirradiated samples was found for irradiation doses of more than 3 kGy for egg white and chicken meat. For shrimps no significant increase of OH-Trp isomers was measured up to a radiation dose of 5 kGy.
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PMID:Determination of hydroxytryptophan isomers in gamma-irradiated egg white, chicken meat, and shrimps. 1072 Nov 19

The real-time uptake of serotonin, a neurotransmitter, by rat leukemia mast cell line RBL-2H3 and 5-hydroxytryptophan by Chinese hamster V79 cells has been studied by fluorescence lifetime imaging microscopy (FLIM), monitoring ultraviolet (340 nm) fluorescence induced by two-photon subpicosecond 630 nm excitation. Comparison with two-photon excitation with 590 nm photons or by three-photon excitation at 740 nm shows that the use of 630 nm excitation provides optimal signal intensity and lowered background from auto-fluorescence of other cellular components. In intact cells, we observe using FLIM three distinct fluorescence lifetimes of serotonin and 5-hydroxytryptophan according to location. The normal fluorescence lifetimes of both serotonin (3.8 ns) and 5-hydroxytryptophan (3.5 ns) in solution are reduced to approximately 2.5 ns immediately on uptake into the cell cytosol. The lifetime of internalized serotonin in RBL-2H3 cells is further reduced to approximately 2.0 ns when stored within secretory vesicles.
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PMID:Real-time cellular uptake of serotonin using fluorescence lifetime imaging with two-photon excitation. 1808 Mar 29


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