肥大细胞释放组胺的机制

<正> 肥大细胞通过胞裂外排的方式释放组胺。有多种物质作用于释放过程的各个环节,相互协调,最终使细胞内颗粒膜彼此融合并与细胞膜融合,排出颗粒内容物。目前,已采用多种实验方法,从不同的角度探讨肥大细胞释放组胺的机制。如广为应用的可通透细胞(Permeabilized cell),即皂甙处理的肥大细胞,可向其中加入外源性的激动剂或抑制剂。利用电压箝技术可研究组胺释放过程中胞膜对离子通透性的改变;利用电镜     

类糜蛋白酶抑制剂对人结肠肥大细胞组胺释放的影响

目的　研究类糜蛋白酶抑制剂对人结肠肥大细胞释放组胺的影响。方法　用酶消化人结肠组织并分离细胞成份。激发过程在LP4试管中、37℃条件下完成。组胺水平用以玻璃纤维为基础的荧光方法测定。结果　类糜蛋白酶抑制剂ZIGPFM、TPCK和α1 抗胰蛋白酶无明显刺激人类结肠肥大细胞释放组胺的作用。 3种类糜蛋白酶抑制剂均可以剂量依赖性方式抑制抗IgE抗体诱导的组胺释放 ,最大浓度的ZIGPFM(1mmol·L-1)、TPCK(80mmol·L-1)和α1 抗胰蛋白酶(30mmol·L-1)可分别抑制 37%、2 6 %和 36 8%的组胺释放。在 37℃条件下同结肠细胞预培养 2 0min与无预培养相比 ,ZIGPFM和TPCK抑制抗IgE抗体诱导的组胺释放的作用略有增强。 3种类糜蛋白酶抑制剂均可以剂量依赖性方式抑制CI诱导的组胺释放 ,最大抑制范围在 2 3 6 %～ 35 %之间。在 37℃条件下同结肠细胞预培养 2 0min与无预培养相比 ,TPCK对CI诱导的组胺释放的抑制作用略有增强 ,但ZIGPFM则无此特点。结论　我们发现了类糜蛋白酶抑制剂可抑制人结肠肥大细胞IgE依赖性和非依赖性组胺释放 ,提示类糜蛋白酶抑制剂可能有抗炎症性肠病的作用 ,可研究开发     

钙离子对4－氨基吡啶诱发肥大细胞释放组胺作用的影响

钙离子对４－氨基吡啶诱发肥大细胞释放组胺作用的影响徐建华，王佩，陈志刚，张剑　（浙江医科大学药学系药理学教研室杭州３１０００６）４－氨基吡啶（４－ａｍｉｎｏｐｙｒｉｄｉｎｅ，４－ＡＰ）是一种钾通道阻滞剂，它能促进神经末梢释放多种递质［１，２］，促进β...     

钙离子对4-氨基吡啶诱发肥大细胞释放组胺作用的影响

4-Aminopyridine(4-AP) has been shown to induce histamine release fromisolated peritoneal mast cells(PMC)in mice and rats. In the presence of extracellular calcium atnormal level(0.9 mmol·L^-1)histamine release induced by 4-AP(13. 6 mmol·L^-1) from mice PMCwas 33.0%±4.6%,while at low calcium concentration (0.5 mmol·L^-1) and in calcium-freemedium this parameter decreased to 25.5%±4.2%and 16.3%±3.7%respectively.Histaminerelease in response to 4-AP(10 mmol·L^-1)from rat PMC was 39.1%±6.7%(0.9 mmol·L^-1calcium),while at low calcium concentration(0. 5 mmol·L^-1) and in calcium-free medium thisparameter decreased to 29.3%±4.7%and 20.2%±2.9% respectively. Results of statisticalanalysis indicate that 4-AP induced histamine release is related to Ca²⁺ concentration. When rat PMCwere preincubated in calcium-free medium with EDTA 0.1 mmol·L^-1 for 180 min　4-AP inducedhistamine release was 13.8%±1.6%.This shows that 4-AP also elicited mobilization of endogenous calcium stores in mast cells.The mechanism of 4-AP　induced histamine release was discussed.     

槲皮素对TNFα诱导的内皮细胞与中性粒细胞粘附的抑制作用

目的:研究槲皮素对TNFα诱导的内皮细胞与中性粒细胞粘附的抑制作用及作用机制.方法:用髓过氧化酶法测定中性粒细胞与内皮细胞的粘附,ELISA法测定内皮细胞粘附分子的表达. 结果:TNFα通过增加/诱导内皮细胞ICAM-1, VCAM-1及E-selectin的表达而剂量、时间依赖性地增加内皮细胞与中性粒细胞的粘附.槲皮素可剂量依赖性地抑制上述粘附,其作用机制为抑制TNFα诱导内皮细胞上述3种粘附分子的表达.结论:槲皮素通过抑制ICAM-1, VCAM-1及E-selectin的表达而降低TNFα诱导的内皮细胞与中性粒细胞的粘附.     

阿魏酸钠对血小板促肥大细胞释放组胺的影响

观察血小板激活前后对肥大细胞释放组胺的影响，发现致敏血小板激活后，与肥大细胞混合，其组胺释放率为８２．３％±５．７％；比未致敏血小板与肥大细胞混合后的组胺释放率５９．０％±９．０％有显著增高（Ｐ＜０．０１），用阿魏酸钠２３ｍｏｌ·Ｌ－１处理血小板后，用药组的肥大细胞组胺释放率３３．４±１５．８％比用药前显著下降（Ｐ＜０．０１），而阿魏酸钠对肥大细胞自身的组胺释放率影响不大，说明阿魏酸钠主要通过抑制血小板激活，而参与抗过敏作用的。     

槲皮素对TNFα诱导的内皮细胞与中性粒细胞粘附的抑制作用

目的:研究槲皮素对TNF_α诱导的内皮细胞与中性粒细胞粘附的抑制作用及作用机制。方法:用髓过氧化酶法测定中性粒细胞与内皮细胞的粘附,ELISA法测定内皮细胞粘附分子的表达。结果:TNF_α通过增加/诱导内皮细胞ICAM-1,VCAM-1及E-selectin的表达而剂量、时间依赖性地增加内皮细胞与中性粒细胞的粘附。槲皮素可剂量依赖性地抑制上述粘附,其作用机制为抑制TNF_α诱导内皮细胞上述3种粘附分子的表达。结论:槲皮素通过抑制ICAM-1,VCAM-1及E-selectin的表达而降低TNF_α诱导的内皮细胞与中性粒细胞的粘附。     

杠柳苷元对肥大细胞脱颗粒及释放组胺影响的研究

目的:研究香加皮提取单体化合物杠柳苷元对大鼠和小鼠肥大细胞脱颗粒及组胺释放的影响。方法:大鼠腹腔注射百日咳疫苗、后腿注射卵白蛋白致敏,用于测定肥大细胞脱颗粒反应及制备抗血清;取致敏大鼠的血清稀释后对小鼠进行腹腔注射,测定肥大细胞脱颗粒反应;以荧光分光光度法测定组胺浓度。结果:杠柳苷元对体外培养肥大细胞的组胺释放有显著的抑制作用,实验剂量即可使组胺释放浓度降低(69.4±8.6)%,其抑制作用呈显著的剂量依赖关系;杠柳苷元对抗原致敏大鼠肥大细胞的组胺释放也有显著的抑制作用,在20μg·mL-1浓度时即可使组胺释放浓度减少73.55%;杠柳苷元口服给予致敏小鼠后,在50mg·kg-1剂量时即可使小鼠组胺释放浓度减少80%以上,并呈显著的剂量依赖关系。结论:杠柳苷元对体外培养的肥大细胞、致敏大鼠肥大细胞的组胺释放有显著的抑制作用;口服给予杠柳苷元可使小鼠显著减少肥大细胞的组胺释放。鉴于肥大细胞脱颗粒及组胺释放在炎症反应中的作用,可认为杠柳苷元是香加皮具有抗炎作用的有效成分之一。     

槲皮素及阿司匹林对血小板与中性粒细胞相互作用的影响

采用血小板聚集及血小板与中性粒细胞形成玫瑰花结试验探讨槲皮素及阿司匹林对血小板与中性粒细胞相互作用的影响. 结果表明,家兔中性粒细胞可抑制ADP诱导的血小板聚集,槲皮素(0.3-100 μmol·L^-1)及阿司匹林(0.4-3.3 mmol·L^-1)可增加中性粒细胞对血小板的抑制作用. 当中性粒细胞被乙酸肉豆寇佛波醇(PMA 100 μg·L^-1)激活时,此抑制作用消失. 槲皮素 (3 μmol·L^-1)可对抗PMA激活中性粒细胞. 即使无中性粒细胞存在,阿司匹林亦可抑制血小板的聚集,但单独槲皮素却不抑制血小板聚集. 槲皮素(3-300 μmol·L^-1)及阿司匹林(0.4-3.3 mmol·L^-1)可浓度相关性地抑制凝血酶激活的血小板与中性粒细胞的粘附.     

促组胺释放的肽类物质*

组胺是各种炎症反应中重要的介质,许多物质都具有导致人体和大鼠肥大细胞释放组胺的不良反应。虽然肽类药物相对于其他药物而言,具有活性高,不良反应小等优点,但一些活性肽类化合物也能引起组胺释放,使得这些肽类药物临床使用受到限制。对肽类物质的组胺释放作用研究,有助于进一步改善肽类药物的某些不良反应,降低其毒性。现列举了部分内源性和外源性的肽类物质,并对其组胺释放作用机制进行了综述。     

FMLP-activated neutrophils evoke histamine release from mast cells

Human neutrophils, having been activated by the chemotactic peptide N-formylmethionyl-leucyl-phenylalanine (FMLP), evoke histamine release from rat serosal mast cells. The release is dependent on FMLP concentration and it can be inhibited by disodium cromoglycate and by a flavonoid, silymarin, which displays free radical scavenging properties. Silymarin inhibition of neutrophil-mediated histamine release is dose-dependent. These results further stress the concept of a neutrophil-mast cell interaction, which may be involved in inflammatory processes.     

Anthracycline-induced histamine release from rat mast cells

Comparisons were made of the ability of doxorubicin, daunorubicin, rubidazone and aclacinomycin A to release histamine from rat peritoneal mast cells. Preliminary in vitro experiments indicated that doxorubicin (10(-6) to 2.5 X 10(-4) M), in contrast to compound 48/80 and the calcium ionophore A23187, did not produce significant release under any condition tested when purified or unpurified rat mast cells were used. In in vitro experiments, released histamine was measured in the cell-free supernatant of peritoneal fluid of rats after intraperitoneal injection of the agents. The time course of doxorubicin-induced histamine release from the peritoneum was rapid, with maximal release occurring within 4 to 6 min. Dose-response curves of the 4 agents over the range 10(-5) to 3.3 X 10(-3) M revealed that all caused histamine release, with 10(-3) M concentrations of each causing maximal release of comparable magnitude to that produced by 9.5 X 10(-6) M A23187. Treated mast cells recovered from the peritoneal cavity showed degranulation and vacuolization when examined by electron microscopy. Increased vascular permeability by the Evans-blue test was also noted with all 4 agents, and zones were of comparable size after injection of the highest concentration of each agent. The results indicate that in vivo, doxorubicin, daunorubicin, rubidazone and aclacinomycin A cause a rapid release of histamine from rat mast cells and an increase in vascular permeability in rat sin. There also appeared to be a reasonable correlation between the blueing reaction and histamine release in the peritoneal cavity in that the doses that did not cause skin blueing also failed to cause histamine release. The lack of histamine release by doxorubicin from mast cell preparations in vitro suggests that alterations to the doxorubicin molecule or the presence of other critical substances may be necessary for this activity to commence.     

Effect of methylmercury on histamine release from rat mast cells

Methylmercury chloride (MeHgCl) is well known as a significant environmental hazard, particularly as a modulator of the immune system. As it is acknowledged that the critical effector cells in the host response participating in various biological responses are mast cells, we tried to define the possible contribution of mast cells in the development of methylmercury-evoked effects. We investigated the effects of methylmercury on the rat mast cell degranulation induced by non-immunological stimuli (the selective liberator of histamine, compound 48/80, and calcium ionophore A23187) both in vivo and in vitro. Using the cells prepared from methylmercury-intoxicated rats through a 5-day treatment of MeHgCl (10 mg/kg/day), we observed the suppression of calcium ionophore A23187- and 48/80-induced histamine release, which was enhanced with time after treatment. Similar suppression was observed in the ionophore-stimulated release, when cells were prepared from rat with a single treatment of MeHgCl (20 mg/kg). It should be noted that when cells from the control rat were pre-incubated with methylmercury in vitro at a 10(-8) M concentration for 10 min, A23187 and compound 48/80-stimulated histamine release was significantly enhanced. However, when the pre-incubation period was prolonged to 30 min, the release was suppressed. An increase in the methylmercury concentration to 10(-6) M also suppressed the histamine release. These results show that methylmercury treatment can modify mast cell function depending on concentration and time, and might provide an insight into the role of mast cells in the development of methylmercury-stimulated effects.     

Inhibitory mechanism of tritoqualine on histamine release from mast cells

Tritoqualine (TRQ, (+)-(R*)-7-amino-4,5,6-triethoxy-3-[(R*)-5,6,7, 8-tetrahydro-4-methoxy-6-methyl-1,3-dioxolo[4,5-g]isoquinolin++ +-5-yl] phthalide) strongly inhibited the increased metabolism of [3H]arachidonic acid-labeled phospholipid and 45Ca2+ influx in mast cells stimulated by compound 48/80 (compd 48/80), Concanavalin A (Con A) plus phosphatidylserine (PS), or 2,4-dinitrophenyl-coupled-ascaris extracts (DNP-asc). However, TRQ did not disturb the binding of 14C-labeled compd 48/80 to the mast cell membrane. The activity of calmodulin purified from mastocytoma P-815 cells was inhibited by TRQ at IC50 1.0 microM. From these results, it is concluded that the inhibitory mechanism of TRQ on stimulus-induced histamine release from mast cells may be mediated at least partially by the inhibition of Ca2+ influx and calmodulin activity.     

Effect of calcium on dextran-induced histamine release from isolated mast cells

Phosphatidyl serine potentiation of dextran-induced histamine release from isolated rat mast cells, was found to be calcium-dependent.     

Dependence of histamine release from rat mast cells on adenosine triphosphate

Summary using pure populations of rat mast cells, the relation of the ATP content of the cells to histamine release induced by compound 48/80 has been studied. Variable ATP levels in the mast cells have been produced by incubation with appropriate concentrations of oligomycin.The dose-response curves of oligomycin for the inhibition of histamine release and for the reduction in the ATP content of the mast cells are similar. The concentration required for 50% inhibition of histamine release is, however, higher than that for 50% reduction of the ATP level.Comparative study of the reduction of the ATP content and the inhibition of histamine release in samples of the same suspension of mast cells shows a linear relation between 10 to 90% inhibition of histamine release and 40 to 95% inhibition of ATP synthesis.The observations support the hypothesis that ATP is involved in the process of histamine release from mast cells induced by compound 48/80.     

Peptides and histamine release from rat peritoneal mast cells

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.     

Effects of cannabinoid receptor agonists on immunologically induced histamine release from rat peritoneal mast cells

Immunologic activation of mast cells through the cross-linking of high affinity IgE receptors results in the release of inflammatory mediators which are important in the pathogenesis of allergic reactions. Early studies investigating the effects of palmitoylethanolamide on animal models of inflammation and on rat mast cells led to the hypothesis that endogenous cannabinoids might act as local autacoids which suppressed inflammation by reducing the activation of mast cells. However, more recent studies produced contradicting results. In order to evaluate if cannabinoid receptors are present in mast cells, we studied the effects of endocannabinoids (anandamide and palmitoylethanolamide) and synthetic cannabimimetics (CP 55,940, WIN 55,212-2 and HU-210) on histamine release from rat peritoneal mast cells. When incubated with mast cells alone, only anandamide could induce significant level of histamine release at concentrations higher than 10(-6) M. When mast cells were activated with anti-IgE, the histamine release induced was not affected by anandamide, palmitoylethanolamide and CP 55,940. In contrast, both WIN 55,212-2 and HU-210 enhanced anti-IgE-induced histamine release at 10(-5) M and preincubation did not increase the potency. The histamine releasing action of anandamide and the enhancing effects of WIN 55,212-2 and HU-210 on anti-IgE-induced histamine release were not reduced by the cannabinoid receptor antagonists, AM 281 and AM 630. In conclusion, the present study does not support the hypothesis that cannabinoids suppress mast cell activation. Instead, some of the cannabinoid receptor-directed ligands tested enhanced mast cell activation. However, the high concentrations required and the failure of cannabinoid receptor antagonists to reverse such effects also question the existence of functional cannabinoid receptors in mast cells.