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1.
The effects of various histamine liberators and inhibitors on isolated rat peritoneal and pleural mast cells have been compared. The pleural cells showed an increased reactivity to challenge with antigen following passive, but not active, sensitization and were more responsive to challenge with anti-IgE. Phosphatidyl serine enhanced the secretion from both cell types. Peritoneal and pleural cells exhibited virtually identical responses after treatment with chemical secretagogues in the presence of exogenous calcium, but the peritoneal cells were significantly more reactive to stimulation with basic inducers in the absence of the cation. Anaphylactic histamine secretion was comparably inhibited by a number of anti-allergic drugs but the peritoneal cells were rather more sensitive to inhibition by dibutyryl cyclic AMP. These results are discussed in terms of the general functional heterogeneity of mast cells from different sources.  相似文献   

2.
Alpha-chymotrypsin was demonstrated to release histamine from rat peritoneal mast cells. Release of histamine was shown by electron microscopy not to be cytotoxic. Release was temperature dependent, required Ca2+ and cell ATP for optimal effect, and involved the direct action of α-chymotrypsin on the mast cells. Trypsin was far less active in releasing histamine, but exposure of the cells to trypsin inhibited the subsequent release of histamine by chymotrypsin. The relationship between the action of exogenous α-chymotrypsin and an endogenous “activatable” esterase could not be established from this set of experiments because the release of histamine by polymyxin B was only slightly inhibitable by the esterase inhibitor, dusopropylfluorophosphate, and, therefore, did not apparently require the participation of the endogenous esterase.  相似文献   

3.
IM: To study the changes of phospholipase D (PLD) activity of actively sensitized rat peritoneal mast cells (RPMC) in degranulation. METHODS: Degranulation of RPMC was determined by measurement of β-hexosaminidase release. PLD activity assay was carried out by measurement of PLD product, choline, with chemiluminescent oxidation of luminol. RESULTS: Actively sensitized RPMC challenged with ovalbumin (0.5-8 mg/L for 120 s, 4 mg/L for 15-120 s) resulted in significant activation of PLD accompanied with the increment of P-hexosaminidase release. PLD activity of sensitized RPMC was increased by more than 2-fold compared with that of unsensitized RPMC which contained low levels of PLD activity [(35±13) pmol choline/min in 1×106cells], but β-hexosaminidase releases of the sensitized cells were as low as spontaneous releases.  相似文献   

4.
Summary The effects of adenosine and its analogues on cAMP-responses and histamine release of rat peritoneal mast cells were investigated. The adenosine analogue 5-N-ethylcarboxamidoadenosine (NECA') activates the adenylate cyclase of the mast cell membranes and elevates the cAMP-levels of the intact mast cells. Both effects are antagonized by methylxanthines, suggesting that they are mediated via an A2 adenosine receptor. Adenosine and its analogues enhance the release of histamine from these cells, when the release is stimulated either by the calcium ionophore A 23187 or by concanavalin A. However, this effect is not antagonized by theophylline or 8-phenyltheophylline. In contrast, it is antagonized by the adenosine uptake blockers S-(p-nitrobenzyl)-6-thioinosine (NBTI) and S-(p-nitrobenzyl)-6-thioguanosine (NBTG). It is concluded that adenosine has two different effects on mast cells: it activates adenylate cyclase via an A2 adenosine receptor, and it enhances histamine release via an action at an intracellular site.Abbreviations NECA 5-N-ethylcarboxamidoadenosine - NBTI S-(p-nitrobenzyl)-6-thioinosine - NBTG S-(p-nitrobenzyl)-6-thioguanosine - PIA N6-phenylisopropyladenosine - Con A concanavalin A Send offprint requests to M. J. Lohse at the above address  相似文献   

5.
Dantrolene strongly and dose-dependently inhibited histamine release from rat peritoneal mast cells induced by anti-IgE. Dantrolene inhibited Ca(2+)-mobilization from intracellular Ca(2+)-store as well as histamine release in mast cells activated by anti-IgE, the effect on both these phenomena being closely correlated. These results suggested that the effect of dantrolene on histamine release from rat mast cell might be due to the inhibition of Ca(2+)-release from intracellular Ca(2+)-store.  相似文献   

6.
Canatoxin, a toxic protein present in the seeds of Canavalia ensiformis, induces the secretion of serotonin, dopamine and insulin through activation of the lipoxygenase pathway. The purpose of the present study was to verify if canatoxin causes histamine release from rat peritoneal mast cells and to perform a detailed study of this phenomenon. Our results indicate that canatoxin is capable of activating mast cells to release histamine. The process is time- and concentration-dependent, occurs without cell damage and requires metabolic energy as well as the presence of divalent cations (Ca2+ and Mg2+). Optimal release occurs at 37 degrees C and at physiological pH. Extremes of temperature (0 degree C and 45 degrees C) inhibit the process. We conclude that canatoxin induces histamine release from rat peritoneal mast cells by an active secretory process.  相似文献   

7.
The apomorphine-induced inhibition of histamine release in rat peritoneal mast cells was studied by means of secretagogues stimulating different pathways of mast cell activation. Apomorphine inhibited the mast cell response to all releasing agents (lysophosphatidylserine plus nerve growth factor, compound 48/80, substance P, ATP, tetradecanoylphorbolacetate, melittin). The IC50 ranged from 4 microM to 24 microM at concentrations of secretagogues releasing 30-50% of mast cell histamine. However, the potency of the drug decreased at higher secretagogue concentrations. Mast cells, pretreated with apomorphine and washed, released little histamine upon stimulation. The secretory response could be partially restored on increasing the concentration of secretagogues. The results suggest that apomorphine affects a regulatory step controlling the terminal sequence of mast cell secretory activity. As indicated by the reduced potency of the drug, the control by the apomorphine-sensitive reaction loses efficiency under conditions of massive histamine release.  相似文献   

8.
Peptides and histamine release from rat peritoneal mast cells   总被引:5,自引:1,他引:5  
Various vasoactive peptides were compared for their histamine releasing effects on rat mast cells. Neurotensin, substance P (SP), and kallidin were the most active natural peptides, followed by bradykinin; neurokinin A and B, bombesin, angiotensin and tuftsin were practically inactive. Several kinins and tachykinin-related peptides were tested in an attempt to characterize the receptors mediating histamine liberation. The order of potency of the kinins was the following: kallidin greater than [Tyr(Me)8]bradykinin = bradykinin greater than [desArg10]kallidin greater than desArg9-bradykinin, the same as that found in smooth muscle possessing receptors of the B2 type. Tachykinin-related peptides were potent stimulants and followed the order: [D-Tryp7,9,10]SP-(1-11) greater than [D-Pro2,D-Tryp7,9,10]SP-(1-11) greater than SP-(1-11) greater than SP-(1-9) greater than [D-Pro4,D-Tryp7,9,Leu11]SP-(4-11) greater than SP-(1-7) greater than SP-(4-11) greater than neurokinin A = neurokinin B, indicating that: (a) undecapeptide antagonists of SP behave as superagonists; (b) both N- and C-terminal portions of SP-(1-11) are essential for activity; and (c) receptors for the tachykinins mediating histamine release appear to be of the SP-P type.  相似文献   

9.
Compound 48/80-induced histamine release (HR) from the isolated perfused rat heart was markedly and significantly inhibited by picumast (PIC), possibly by acting as a calmodulin antagonist (CMA) or membrane stabilizer. Trifluoperazine (TFP, another CMA in clinical use) had a similar effect. However, an action as CMA being the basis of inhibition of HR could not be confirmed in another 'allergy' model, namely HR from rat peritoneal mast cells (RPMC). PIC, TFP and two other CMA, W7 and N-(4-aminobutyl)-5-chloro-1-naphthalenesulfonamide) failed consistently to inhibit 48/80-induced HR from RPMC, and when used on their own at high concentration these compounds caused HR. PIC and TFP also potentiated the heat-induced haemolysis of rat erythrocytes, i.e. lacked membrane stabilizing effect in this model.  相似文献   

10.
1 Ions of the lanthanide series (lanthanum-lutetium) inhibit histamine release induced by allergen and anti-IgE in the presence of extracellular calcium. The inhibition is dose-dependent in the range 10(-6) to 10(-9) M and there is no marked difference in potency between the lanthanides. 2 The response to lanthanum is biphasic and higher concentrations (10(-4) M) potentiate the release. Maximal concentrations (10(-3) M) again abolish secretion. 3 The effect of concanavalin A is weakly antagonized by lanthanum but strongly inhibited by higher lanthanides. 4 Inhibition of histamine release evoked by basic agents is markedly dependent on the ionic radius of the lanthanide. In the presence of extracellular calcium, dysprosium is the most effective inhibitor. Similar results are observed with dextran. In the absence of calcium, there is a regular increase in inhibition with decreasing ionic radius. 5 Inhibition of release in the presence of calcium is immediate and does not require preincubation with the lanthanide. The antagonism due to lanthanum is competitive and the pA2 values vary with the secretagogue. In contrast, the inhibitory effect in the absence of extracellular calcium increase progressively with time. 6 These results are discussed in terms of the calcium-pools important in histamine release and the mode of action of different secretagogues.  相似文献   

11.
采用主动致敏的大鼠腹腔肥大细胞 (RPMC)为实验材料 ,细胞脱颗粒以 β 氨基己糖苷酶释放率为指标 ,细胞磷脂酶D(PLD)活性采用酶联化学发光法检测 .结果发现 ,卵白蛋白 (4mg·L- 1)攻击主动致敏的RPMC 12 0s后 ,细胞PLD活性与β 氨基己糖苷酶释放率均明显增加 ,分别为对照组的 2倍及 8倍以上 .1%正丁醇 ,10mmol·L- 12 ,3 二磷酸甘油酸能显著抑制PLD活性 ,且使PLD活性及细胞 β 氨基己糖苷酶释放率均降低到对照水平 .Wortmannin ,30 0nmol·L- 1能显著抑制PLD活性 ,并减少细胞 β 氨基己糖苷酶释放 .1,10 μmol·L- 1的沙丁胺醇与色甘酸钠均能部分抑制PLD活性 ,并减少细胞 β 氨基己糖苷酶的释放 .结果表明 ,PLD在主动致敏的RPMC脱颗粒过程中起一定作用 ;沙丁胺醇 (1,10 μmol·L- 1) ,色甘酸钠 (1,10 μmol·L- 1)抑制主动致敏的RPMC脱颗粒的作用机理与抑制PLD有关 .  相似文献   

12.
13.
Proteins in the plasma membranes of rat peritoneal mast cells   总被引:1,自引:0,他引:1  
Plasma membranes of peritoneal mast cells from rats specifically bred for resistance to the dextran anaphylactoid reaction contain a polypeptide of molecular weight about 74,000 daltons which is deficient in those from rats which react to dextran. This polypeptide may modify the dextran receptor on the mast cell membranes of resistant rats so that histamine release does not take place when these cells are challenged with clinical dextran.  相似文献   

14.
The actions of the polyamines compound 48/80, poly-l-lysine and polymyxin B on rat pleural and peritoneal mast cell secretion have been studied. Unpurified pleural mast cells released more histamine than peritoneal mast cells when stimulated by submaximal concentrations of compound 48/80 and poly-l-lysine, but the same profile of response was observed with polymyxin B in both populations. Dose-response studies of peritoneal and pleural mast cells purified with Percoll and Ficoll and stimulated by polymyxin B showed a decreased sensitivity and decreased maximum response of peritoneal cells when Percoll was used. The maximal response of pleural cells and the sensitivity of peritoneal cells were affected only slightly by Ficoll.  相似文献   

15.
We have examined the effect of a range of histamine H1- and H2-receptor agonists and antagonists on rat peritoneal mast cells. Most of the compounds had a dual action: at low concentrations they inhibited the histamine release produced by immunologic activation of the cell whereas at higher concentrations they themselves induced a cytotoxic release of the amine. The test agents did not affect intracellular levels of cyclic AMP. In model systems, the majority of the drugs had no effect on the integrity of artificial liposomes but did protect rat erythrocytes against osmotic shock. We then propose that these agents produce their effects on mast cells by a direct action on the cell membrane, with low concentrations becoming incorporated into the bilayer in such a way as to stabilize the structure and high concentrations disrupting the membrane and leading to cell lysis.  相似文献   

16.
Activation of protease-activated receptor (PAR)-1 or PAR-2 elicits inflammation most probably via mast cell degranulation in vivo. The present study aimed at characterizing PARs in rat peritoneal mast cells (PMC). Messenger RNA for PAR-1, but not for PAR-2, was detected in PMC. Thrombin, the PAR-1 agonist SFLLR-NH2 or the PAR-2 agonist SLIGRL-NH2 failed to induce histamine release from PMC. Surprisingly, the PAR-2-inactive control peptide LSIGRL-NH2 triggered histamine release from PMC. Thus, PAR-1, but not PAR-2, are expressed in PMC, whereas neither PAR-1 nor PAR-2 are considered to be involved in degranulation of PMC. LSIGRL-NH2 does not appear to be appropriate as a control peptide for PAR-2 in inflammation studies.  相似文献   

17.
The effect of the monovalent carboxylic ionophore monensin, which mediates a one-for-one exchange of intracellular H+ for extracellular Na+, was investigated in purified rat peritoneal mast cells. Monensin inhibited histamine secretion induced by compound 48/80, adriamycin and the calcium ionophore A23187; the inhibitory effect was maximal when the compound was added at least 10 min before the secretagogues. Washing of cells before addition of the secretagogues did not abolish the inhibitory effect of monensin. On the contrary the carboxylic ionophore was completely ineffective in preventing concanavalin A-induced histamine release. When rat peritoneal mast cells were incubated in the presence of monensin for longer period (up to 5 hours), the substance induced a slow, progressive and dose dependent histamine release, which, at least for lower doses was noncytotoxic. The secretory effect of monensin was still present if the ionophore was washed away after 10 min of incubation, and the incubation continued in drug-free medium. Monensin stimulated histamine secretion was strictly dependent on extracellular Na+ concentrations, and independent on extracellular Ca++.  相似文献   

18.
Desensitization of rat peritoneal mast cells to substance P   总被引:1,自引:0,他引:1  
Rat peritoneal mast cells were pretreated for 10 min at 37 degrees C with either substance P (SP, 3 or 6 microM) or compound 48/80 (37.5, 50 or 75 ng/ml). The effect of this pretreatment on the subsequent responsiveness of the cells to SP was studied. Both SP and compound 48/80 pretreatment of rat peritoneal mast cells inhibited the subsequent response of the cells to SP. The degree of inhibition produced by either SP or compound 48/80 was dependent on the concentration used to pretreat the cells. Inhibition of the response of the cells to SP was observed whether or not the pretreating agent was removed or remained in contact with the cells during the subsequent stimulation with SP. It is concluded that compound 48/80 and SP desensitize the cells to subsequent stimulation by SP and possible mechanisms for this are discussed.  相似文献   

19.
Human salivary histatins (Hsts), which belong to a salivary polypeptide family, have potent antifungal activity against Candida albicans and Cryptococcus neoformans, and are expected to be useful as therapeutic reagents against Candida species. However, little is known about the effect of Hsts on host immune systems. Thus we conducted a series of in vitro experiments with rat mast cells to determine whether histatin 5 (Hst 5) or histatin 8 (Hst 8) has a histamine-releasing effect on mast cells. Both Hst 5 and Hst 8 induced histamine release from rat peritoneal mast cells in a dose-dependent manner (10(-9) to 10(-5) M). Hst 5 had a stronger releasing effect than Hst 8. The histamine release induced by Hst 5 (10(-6) M) was increased by the presence of 0.5 mM Ca2+, but decreased by 2mM Ca2+. Alternatively, the histamine release induced by Hst 8 (10(-6) M) was inhibited by the presence of Ca2+ (0.5 to 2 mM). These results suggest that Hsts have limited usefulness as therapeutic agents due to induction of histamine release from mast cells.  相似文献   

20.
The effect of platelet-activating factor (PAF) on histamine release from peritoneal mast cells of adult and young male rats was investigated. PAF alone tended to release histamine from the mast cells of adult and young rats, although very slightly. On the other hand, PAF significantly inhibited the histamine release induced by the Ca2+ ionophore A23187 in mast cells obtained from rats of either age group, but not that by compound 48/80. Such inhibition was not seen with lyso-PAF. CV-3988, a PAF antagonist, antagonized the inhibitory effect of PAF on the A23187-induced histamine release in mast cells from adult and young rats. These results suggest that PAF does not have a strong histamine-liberating action on mast cells, and that PAF inhibits the calcium influx into mast cells through the activation of PAF receptors.  相似文献   

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