竞争性蛋白结合法检测囊尾蚴病患者血浆中cAMP含量

人体感染囊尾蚴后,患者血清中具有高水平的总IgE;并与特异性IgE同步增加。经间接非特异性及特异性肥大细胞脱颗粒试验进一步证实,囊尾蚴病患者的血清中确实存在特异性IgE,致敏的肥大细胞在囊尾蚴抗原作用下发生脱颗粒反应;释放出组织胺等生物活性物质。鉴于IgE及其介导的免疫反应还涉及cAMP的含量,因此,本文应用竞争性蛋白结     

荧光法检测囊虫病患者血清中组织胺含量

应用荧光法分别检测了35例囊虫病患者和35例献血员血清中组织胺的含量。囊虫病患者和献血员血清中的组织胺平均含量为5.3±2.4μg/ml和2.7±1.2μg/ml,两者间差异非常显著(P<0.01)。说明该病患者的血清中存在特异性IgE,致敏的肥大细胞和嗜碱性粒细胞在囊虫抗原作用下能够发生脱颗粒反应;释放出组织胺等生物活性物质。     

粉尘螨口服滴剂抗过敏作用的实验研究

目的探讨粉尘螨口服滴剂的抗过敏作用特点。方法采用豚鼠回肠平滑肌过敏收缩实验和肺支气管灌注法观察粉尘螨口服滴剂对平滑肌的抑制作用 ;大鼠被动皮肤过敏反应观察其对血管通透性改变的影响和颅骨骨膜法观察其对肥大细胞脱颗粒的抑制作用。结果粉尘螨口服滴剂能够明显抑制回肠平滑肌和拮抗抗原对支气管平滑肌的收缩作用 ,对肥大细胞脱颗粒具有显著的抑制作用。结论粉尘螨口服滴剂具有显著的抗过敏作用     

粉尘螨口服滴剂抗过敏作用的实验研究

目的：探讨粉尘螨口服滴剂的抗过敏作用特点。方法：采用豚鼠回肠平滑肌过敏收缩实验和肺支气管灌注法观察粉尘螨口服滴剂对平滑肌的抑制作用；大鼠被动皮肤过敏反应观察其对血管通透性改变的影响和颅骨骨膜法观察其对肥大细胞脱颗粒的抑制作用。结果：粉尘螨口服滴剂能够明显抑制回肠平滑肌和拮抗抗原对支气管平滑肌的收缩作用，对肥大细胞脱颗粒具有显的抑制作用。结论：粉尘螨口服滴剂具有显的抗过敏作用。     

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。     

硝苯苄胺啶(yc—93)的抗过敏药理作用

小鼠静注10mg/kgYC-93能显著抑制PCA反应,并能抑制大鼠颅骨骨膜肥大细胞的脱颗粒。本品对致敏豚鼠肺组织因抗原攻击所致的肺灌流量减少具有拮抗作用,使灌流量基本不变。并对致敏和正常豚鼠因抗原和组胺及SRS-A所诱导的喘息具有平喘作用。     

地塞米松抑制肥大细胞脱颗粒及其机制初探

目的：研究糖皮质激素对Ⅰ型超敏反应中的肥大细胞脱颗粒反应是否有直接作用。方法：利用流式细胞仪技术观察地塞米松对RBL-2H3细胞(大鼠嗜碱粒细胞)脱颗粒程度的影响，利用western blot分析：ERK1／ERK2信号的改变。结果：地塞米松预先作用于RBL-2H3细胞，使AnnexinV标记的细胞阳性率较致敏原活化组明显下降，MAPK活性明显降低。结论：地塞米松抑制肥大细胞脱颗粒反应，其机制与MAPK活性有关。     

盐酸普鲁卡特罗的主要药效学研究

观察了盐酸普鲁卡特罗对豚鼠的整体平喘和对离体气管的扩张作用,以及对抗原所致大鼠肥大细胞脱颗粒的抑制作用.结果表明,盐酸普鲁卡特罗有明显的扩张支气管平滑肌作用和平喘作用,对I型变态反应有抑制作用.     

牛膝多糖对抗原诱导的肥大细胞活化的影响

目的观察牛膝多糖(achyranthes bidentata polysaccha-rides,ABPS)对肥大细胞活化脱颗粒的影响。方法运用大鼠被动皮肤过敏反应(PCA)实验,用比色测定法检测ABPS在体内对肥大细胞(MC)影响;体外实验将ABPS分为高、中、低3个剂量组,然后分别将其加入抗原致敏的RBL-2H3细胞中(大鼠嗜碱性粒细胞白血病细胞,国际公认的MC研究模型细胞),观察ABPS对RBL-2H3细胞脱颗粒的影响。结果ABPS能明显抑制大鼠PCA、RBL-2H3细胞脱颗粒,并能抑制RBL-2H3细胞释放组胺、肿瘤坏死因子α及白细胞介素4;抑制RBL-2H3细胞中Akt和p38的磷酸化。结论ABPS的抗过敏作用与抑制肥大细胞的脱颗粒及炎性物质释放有关;ABPS抑制肥大细胞的活化与抑制Akt和p38的活性相关。     

中药桑寄生的抗Ⅰ型变态反应作用

目的:从传统中药中筛选抗Ⅰ型变态反应物质.方法:体外和体内(口服)给药,使用肥大细胞作为靶细胞,观察药物对其脱颗粒和释放组胺的影响.结果:桑寄生提取物(HT)对刀豆蛋白(Con A)诱导的肥大细胞脱颗粒呈明显的抑制作用,且呈剂量依赖关系.对卵白蛋白致敏大鼠肥大细胞的脱颗粒,桑寄生提取物同样有明显的抑制作用.口服该提取物也能抑制组胺的释放,抑制率达85%.结论:桑寄生提取物在体内外都显示出对肥大细胞的脱颗粒反应有非常显著的抑制作用.该提取物有可能开发成防治速发型变态反应的药物.     

Inhibition of C5a-induced basophil degranulation by disodium cromoglycate

Injection of purified porcine C5a into 24-hr basophil-rich cutaneous basophil hypersensitivity sites in the dose range 10(-12)-10(-10) moles/site produced cutaneous basophil anaphylaxis (CBA). The H1 antihistamine antagonist mepyramine, given orally (3.0-30 mg/kg), inhibited the vasopermeability, but not the basophil degranulation, characteristic of CBA. The antiallergy agent disodium cromoglycate (DSCG), administered intravenously (3.0-30 mg/kg), inhibited vasopermeability and basophil degranulation. DSCG inhibition of mast cell degranulation was not important in the inhibition of CBA, since intact mast cells were found to be depleted at basophil-rich sites and absent at C5a-induced CBA sites from animals treated with DSCG. C5a at 10(-11) moles/site also induced vasopermeability and mast cell degranulation in normal guinea pig skin. Vasopermeability, but not mast cell degranulation, was inhibited by mepyramine at 30 mg/kg p.o. However, DSCG at 10 mg/kg i.v. failed to inhibit either the vasopermeability or the mast cell degranulation of this reaction. These results indicate that C5a induces the degranulation of both basophils and mast cells in the guinea pig, and that C5a-induced degranulation of basophils, but not mast cells, is inhibited by DSCG.     

Excavation of lead compounds that inhibit mast cell degranulation by combinatorial chemistry and activity-guided

An allergic reaction ensues after antigen binds to mast cell or basophil high affinity IgE receptor, Fc epsilonRI, resulting in degranulation of various inflammatory mediators that produce various allergic symptoms. In this study, i) we isolated the active component for the inhibition of mast cell degranulation from the extract of leaves of Castanea crenata and identified it as quercetin; ii) we established the total synthesis procedure of quercetin; iii) using quercetin as positive control, we excavated some lead compounds that possess inhibitory activities for mast cell degranulation by screening the chemical libraries of 1,3-oxazolidine derivatives prepared by solid phase combinatorial chemistry. Some of 1,3-oxazolidine compounds possessing acetyl and 3',4'-dichlorophenyl group displayed strong inhibitory activities on Fc epsilonRI-mediated mast cell degranulation, suggesting that they can be used as lead compounds for the development of anti-allergic agents.     

Inhibitory effects of parthenolide on antigen-induced microtubule formation and degranulation in mast cells

Pharmacological modulation of IgE-mediated mast cell activation is important to the development of anti-allergic reagents. In this study, we investigated the effects of parthenolide (PTL) on high-affinity IgE receptor (FcepsilonRI)-induced degranulation in mast cells. PTL dose-dependently inhibited degranulation induced by IgE.antigen stimulation in RBL-2H3 cells and BMMCs. Although PTL is a potent NF-kappaB inhibitor by targeting IkappaB kinase complex, NF-kappaB inhibition by other IkappaB kinase inhibitors did not inhibit degranulation in mast cells. IgE.antigen-induced microtubule formation is well known to be critical for degranulation in mast cells. Immunocytochemical study with anti-alpha-tubulin antibody revealed that PTL significantly inhibited IgE.antigen-induced microtubule formation. However, PTL, as well as nocodazol, had no significant effects on degranulation in the fyn-deficient BMMCs, suggesting that inhibitory effects of PTL in the microtubule formation are fyn dependent. We further demonstrated that in vivo administration of PTL in mice strongly inhibited passive cutaneous anaphylaxis reaction. The present study provides a possibility to develop potent reagents against mast cell activation based on an inhibition of microtubule formation.     

Evaluation of mast cell activation (tryptase) in two patients suffering from drug-induced hypotensoid reactions

Tryptase is predominantly found in mast cells, where it resides in secretory granules, and is released with other mediators during mast cell degranulation. By using a newly developed commercial assay for measurements of tryptase levels we have investigated two cases of suspected drug-induced anaphylaxis. Each patient had a similar clinical presentation, consisting of hypotension and cyanosis after administration of thiopentone and suxamethonium. One of the patients showed a highly elevated serum level of tryptase reaching 26 micrograms/l 30 min after the initial reaction. In addition, slightly elevated levels of specific IgE antibodies to thiopentone were detected. The other patient with similar symptoms showed no increase in the level of tryptase, nor any specific IgE to thiopentone or suxamethonium. These data indicate the patient I suffered from true anaphylaxis, whereas the reaction of patient II occurred by a different mechanism.     

Confocal laser scanning microscopy to study molecular mechanism of mast cell activation

In the immune system, mast cells are a key cell type in the pathogenesis of immunoglobulin E (IgE)-dependent hypersensitivity reactions. Engagement of the high-affinity IgE receptors by multivalent antigens initiates the downstream activation of signal-transducing enzymes and evokes degranulation and cytokine production via an increase in the intracellular Ca2+ concentration. In addition, mast cells also play a prominent role in non-IgE-mediated hypersensitivity reactions. Mast cells are closely apposed to nerves in vivo and are likely to be regulated functionally by nerves. However, the molecular mechanisms for mast cell activation in an IgE-dependent and -independent manner have not been fully clarified. Confocal laser scanning microscopy has played an essential role in cell biology by allowing visualization of specific intracellular signaling molecules with high spatiotemporal resolution in living cells. We have studied intracellular movements of Ca2+ using a specific fluorescent probe and several types of signaling molecules using derivatives of green fluorescent protein in a living single mast cell using a microscopic strategy. We here describe our imaging analysis of the calcium signals to the nucleus, the movement of secretory granules in the degranulation process, and the nucleocytoplasmic shuttling of mitogen-activated protein kinase in mast cells. Further, we demonstrate that direct communication between mast cells and nerves occurs. These findings provide useful information from a new perspective to understand the molecular mechanisms of allergic reaction and inflammation.     

Endogenous nitric oxide does not modulate mesenteric mast cell degranulation in rats

The inhibitory effects of endogenous nitric oxide could explain the decreased mesenteric mast cell degranulation after anaphylaxis in genetically hypertensive rats (SHR). SHR and normotensive rats (NT) were sensitized to ovalbumin and challenged 14 days later. Degranulation of mast cells was assessed in duodenum, mesentery and skin by increased microvascular permeability using extravasation of Evans blue dye (20mg/kg, i.v.), and in the mesentery also by light microscopy after staining with toluidine blue. Pretreatment with an inhibitor of nitric oxide synthesis, L-NAME (30 mg/kg, i.v.) did not change dye extravasation after immunological challenge or after compound 48/80 in mesentery of either SHR or NT. PCA was also defective in SHR. Pretreatment with L-NAME did not affect either the defective PCA in SHR or the normal PCA reaction in NT. Our results show that inhibition by endogenous nitric oxide is not the cause of the defective mast cell degranulation in the SHR nor did it modulate degranulation of mesenteric or skin mast cells in NT.     

Naloxone-induced morphine withdrawal increases the number and degranulation of mast cells in the thalamus of the mouse

Naloxone-induced jumping in morphine-dependent mice is inhibited by cromolyn, a mast cell stabilizer, suggesting that this characteristic withdrawal behavior results from degranulation of mast cells. Because withdrawal is considered as a central phenomenon, degranulation of mast cells located within the CNS may influence aspects of opioid withdrawal. The present study evaluates histologically whether naloxone, injected into opioid dependent mice, induces degranulation of mast cells. Seventy-two hours after the s.c. implantation of a 75 mg morphine pellet, the number and degranulation of thalamic mast cells did not differ from those in placebo-implanted controls. However, two injections of 50 mg/kg of naloxone, 30 and 60 min before tissue collection, increased the number of degranulated mast cells compared to those in mice injected with saline. Analysis throughout the entire thalamus (90 40-micro sections) revealed increases in the total number of mast cells as well as the number that were degranulated, especially in sections 52-60, corresponding to Bregma -2.18 to 2.54. Here, mast cells were clustered in the IGL and VPL/VPM nuclei, and redistributed from the ventromedial to the dorsolateral aspects of the Po and PF nuclei during withdrawal. Degranulation was also greater throughout the LD, LP nuclei during withdrawal. These data reveal a novel neuroimmune reaction to opioid withdrawal in the CNS.     

Mast cell degranulation in rat mesenteric venule: effects of L-NAME, methylene blue and ketotifen.

Mast cells are present in proximity to the microvessels, and on stimulation with inhibition of NO synthesis, are a rich source of numerous inflammatory mediators. A microcirculatory study was undertaken to clarify whether nitric oxide (NO) and activation of guanylate cyclase is involved in degranulation of perivascular mast cells in the rat mesenteric venule, and whether oral administration of ketotifen suppress the degranulation. Intravital microscopy was used to monitor the rates of adherence and extravasation of leukocytes in single unbranched venules with diameters between 25 and 35 microm of rat mesentery. Leukocyte rolling velocity, red blood cell velocity, vessel diameter and blood pressure were also measured. Mast cell degranulation was quantified within 30 microm from the venule. NG-nitro-L-arginine methyl ester (L-NAME) at an intravenous dose of 30 mg kg-1 increased the number of degranulated cells, while its enantiomer, D-NAME at the same dose had no effect. Superfusion with methylene blue (MB), an inhibitor of soluble guanylate cyclase, at 50 microm elicited similar degranulation of the mast cells. The degranulation was associated with increased adhesion of leukocytes to the endothelium and the slowed rolling. Pretreatment with ketotifen at an oral dose of 1 mg kg-1 inhibited mast cell degranulation in responses to either L-NAME or MB. It is conceivable that guanylate cyclase for NO production pathway in endothelial and/or mast cells is involved in the mast cell degranulation process, and the process or subsequent action of NO may be preserved by ketotifen, eliciting down-modulation of mast cell activation.