花青素对IgE介导的肥大细胞活化的影响

观察花青素 (anthocyanidin) 对肥大细胞活化脱颗粒的影响。通过大鼠被动皮肤过敏反应 (PCA) 实验, 采用比色测定法检测花青素在体内对肥大细胞的影响; 体外观察花青素对肥大细胞脱颗粒, 细胞内钙摄入, 肿瘤坏死因子-α (TNF-α) 及白细胞介素6 (IL-6) 释放以及p38MAPK、Akt、NF-κB磷酸化的影响。动物实验显示, 花青素 (50和100 mg·kg⁻¹) 明显抑制大鼠PCA。细胞实验显示, 花青素 (50和100 µmol·L⁻¹) 抑制肥大细胞释放组胺、TNF-α及IL-6, 并可抑制 p38MAPK、Akt和NF-κB的磷酸化。结果提示, 花青素的抗过敏作用与其抑制肥大细胞的脱颗粒, 抑制组胺、TNF-α、IL-6等炎症介质释放以及抑制细胞内钙摄入有关; 花青素抑制肥大细胞的活化可能与其抑制NF-κB、p38MAPK和Akt的活性相关。     

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.     

钾通道开放剂的抗过敏作用及其机制

用多种抗变态反应实验方法,研究钾通道开放剂米诺地尔(Min)与二氮嗪(Dia)的抗过敏作用,并探讨其作用机制。结果表明,Min能抑制大鼠同种被动皮肤过敏反应,拮抗5-HT引起的大鼠皮肤血管通透性增高。Dia和Min均能抑制豚鼠离体回肠平滑肌的过敏性收缩,Dia并能抑制A₂₃₁₈₇和化合物48/80诱发的肥大细胞释放组胺。因此钾通道开放剂Min与Dia具有抗过敏作用,作用的主要机理是抑制肥大细胞外Ca²⁺内流和细胞内贮存钙的释放,从而抑制组胺的释放,此可能与药物开放钾通道的作用有关。     

白芷挥发油抗过敏的实验研究

目的研究白芷挥发油(EOAD)抗过敏作用。方法采用大鼠同种被动皮肤过敏反应(PCA),大鼠颅骨骨膜肥大细胞脱颗粒,组胺致小鼠毛细血管通透性增高的实验。结果与对照组比较,EOAD低剂量组对PCA、大鼠颅骨骨膜肥大细胞脱颗粒、组胺致小鼠毛细血管通透性增高有显著差异,EOAD高剂量组对PCA、大鼠颅骨骨膜肥大细胞脱颗粒、组胺致小鼠毛细血管通透性增高有非常显著差异。结论EOAD具有抗过敏作用,可用于过敏性疾病的治疗。     

白芷挥发油抗过敏的实验研究

目的 研究白芷挥发油(EOAD)抗过敏作用.方法 采用大鼠同种被动皮肤过敏反应(PCA),大鼠颅骨骨膜肥大细胞脱颗粒,组胺致小鼠毛细血管通透性增高的实验.结果 与对照组比较,EOAD低剂量组对PCA、大鼠颅骨骨膜肥大细胞脱颗粒、组胺致小鼠毛细血管通透性增高有显著差异,EOAD高剂量组对PCA、大鼠颅骨骨膜肥大细胞脱颗粒、组胺致小鼠毛细血管通透性增高有非常显著差异.结论 EOAD具有抗过敏作用,可用于过敏性疾病的治疗.     

辛夷酯素抗过敏作用机理探讨

目的探讨辛夷酯素抗过敏作用机理,为指导抗过敏药物的研发及指导I临床用药提供参考及思路。方法分别用形态法和荧光法观察辛夷酯素药物血清冻干粉对致敏大鼠腹腔肥大细胞（PMC）脱颗粒和组织胺释放的影响,研究辛夷酯素的抗过敏作用,探讨抗过敏机制。结果给药15rain、60rain后,制备的药物血清冻干粉对PMC脱颗粒和组织胺释放有明显的抑制作用,且存在一定的时效关系。其抗过敏的机理可能与其稳定肥大细胞细胞膜,抑制其脱颗粒和释放过敏介质有关。结论辛夷酯素对过敏症状有明显的抑制作用,其抗过敏机制与抑制PMC释放过敏性介质组织胺有关。     

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。     

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     

蛇床子挥发油止痒作用相关机制研究

目的　研究蛇床子挥发油止痒作用的机制。方法　用形态法观察了蛇床子挥发油对组胺兴奋豚鼠离体回肠和致敏大鼠腹腔肥大细胞 (PMC)脱颗粒的影响。结果　蛇床子挥发油对组胺引起的离体回肠平滑肌收缩和PMC脱颗粒有明显的抑制作用。结论　蛇床子挥发油止痒作用与拮抗组胺和抑制肥大细胞脱颗粒作用有关     

Effects of Clostridium botulinum C2 toxin-induced depolymerisation of actin on degranulation of suspended and attached mast cells

We studied the effects of C. botulinum C2 toxin, which ADP-ribosylates G-actin, on mast cell degranulation. C2 toxin inhibited degranulation of suspended rat peritoneal mast cells induced by compound 48/80 and dinitrophenyl-conjugated bovine serum albumin (DNP-BSA) maximally by about 50 and 90%, respectively. Inhibition by C2 toxin occurred in a time- and concentration-dependent manner. Half-maximal inhibition of DNP-BSA-induced degranulation by C2 toxin occurred at about 0.015 ng/ml, whereas stimulation of mast cells induced by compound 48/80 was half-maximally inhibited at 0.15 ng/ml C2 toxin. C2 toxin also inhibited stimulated [³H]serotonin release from suspended mast cells. Phorbol 12-myristate 13-acetate (PMA)-induced histamine release of suspended mast cells was inhibited by C2 toxin by about 80–90%. C2 toxin had no effect on calcium ionophore A23187-induced histamine release. Toxin treatment of mast cells caused ADP-ribosylation of actin and depolymerisation of F-actin. Attachment of mast cells, which largely increased the diameter of the subcortical actin network, reduced degranulation stimulated by compound 48/80, antigen and calcium ionophore but not by PMA. Opposite to its effect on suspended cells, in adherent mast cells C2 toxin stimulated degranulation by compound 48/80, antigen, and calcium ionophore but not by PMA. The data indicate that mast cell degranulation and responsiveness towards the actin-depolymerising C2 toxin depend largely on mast cell attachment. Received: 7 October 1996 / Accepted: 22 November 1996     

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.     

Degranulation of mast cells and inhibition of the response to secretory agents by phototoxic compounds and ultraviolet radiation

The symptoms of cutaneous phototoxicity from coal tar compounds and the nonsteroidal anti-inflammatory drug benoxaprofen are characterized by wheal and flare formation which is mediated by histamine released from dermal mast cells. Rat serosal mast cells were used as an in vitro model system to study the direct effect of phototoxic compounds on mast cell degranulation. The coal tar compounds studied included acridine and pyrene. Combined exposure of cells to acridine and UVA (320 to 400 nm) radiation caused mast cells to degranulate, as assayed by the release of [3H]serotonin. Maximum [3H]serotonin release (70 to 80%) was obtained with 50 microM acridine and 300 kJ/m2 UVA. Pyrene (25 microM), when photoexcited with UVB (280 to 360 nm) radiation, caused about 80% release of [3H]serotonin. No degranulation occurred with 20 microM benoxaprofen and UVB doses up to 7.2 kJ/m2. Trypan blue staining correlated well with degranulation caused by acridine plus UVA; however, with pyrene plus UVB there was greater [3H]serotonin release than dye uptake. Excitation of photosensitizers with doses of UV radiation that did not cause trypan blue staining suppressed degranulation of mast cells in response to chemical stimulation. Acridine, pyrene, and benoxaprofen in the presence of UV radiation inhibited the mast cells from responding to compound 48/80 or the calcium ionophore, chlortetracycline. Two other phototoxic compounds, chlorpromazine and deoxytetracycline, also abolished degranulation by compound 48/80. These findings indicate that phototoxic compounds: (1) cause degranulation in the presence of high doses of UV radiation; and (2) suppress degranulation of mast cells in response to secretory stimuli at doses of UV radiation that do not cause release of mediator.     

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.     

Mast cell degranulation in hemorrhagic shock in rats and the effects of vasoactive intestinal peptide, aprotinin and H1 and H2-receptor blockers on degranulation.

Various stressful stimuli cause mast cell degranulation. Hemorrhagic shock is one such stressful stimulus which may cause mast cell degranulation and histamine release. Histamine may be involved in the pathophysiology of hemorrhage. It was reported that there are large amounts of histamine in the anterior and posterior lobes of the pituitary and the adjacent median eminence of the hypothalamus. Most of the histamine in the posterior pituitary is in mast cells. In addition, both vasoactive intestinal peptide (VIP) and histamine-containing neurons are available in the hypothalamus. It therefore seems reasonable to suppose that these three systems (i.e., mast cells, VIP-containing neurons, and histamine-containing neurons) may play an important role in the progression of hemorrhagic shock. 66 albino rats (200-250 g) of either sex were used. The presence of mast cells was examined by light microscopy. Hemorrhage caused mast cell degranulation in a correlation with the amount of blood loss. In all cases, the most intense degranulation was observed in the hypothalamus, especially the nucleus arcuatus, and in the subcutaneous tissue. The intensity of degranulation gradually decreased in the peripheral blood vessel, peritoneum and omentum, in this order. VIP prevented degranulation, but aprotinin and H1 and H2 receptor blockers did not.     

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.     

Changes in membrane potential induced by compound 48/80 in the peritoneal mast cells of rats

The changes in membrane potential induced by compound 48/80 were studied using rat peritoneal mast cells. The mean resting membrane potential of rat mast cells was -12.3 +/- 0.7 mM. When compound 48/80 was added to the mast cells, the cells were degranulated approximately 120 sec after the addition of the drug, after which immediate depolarization occurred. Degranulation of mast cells was not observed, even under the depolarization or hyperpolarization conditions caused by the replacement of a high K+ medium or the removal of K+ from the medium, respectively. Under both conditions, when compound 48/80 was added to the mast cells, degranulation was observed. Abrupt and marked depolarization was induced 30-60 sec after compound 48/80 was added. In addition, repolarization followed by gradual depolarization was observed without degranulation in mast cells treated with cytochalasin D after the addition of compound 48/80. These results suggest that the mast cells were depolarized by compound 48/80 independently of degranulation. It is also feasible that the gradual depolarization and repolarization induced by compound 48/80 in mast cells pretreated with cytochalasin D participated in the extracellular Na+ and Na+/K(+)-pump, respectively.     

The effect of capsaicin application on mast cells in normal human skin

Peptides released from sensory nerves during an axon reflex are thought to cause mast cell degranulation, histamine (Hi) release and Hi-induced vasodilatation leading to the flare of the triple response. Capsaicin stimulates peptide release from sensory neurones and causes flare in vivo but does not cause Hi release from mast cells in vitro. The effects of capsaicin on mast cell degranulation in human skin in vivo has been studied by histological examination of skin biopsies after topical capsicin (1%) treatment of stratum corneum-denuded forearm in four volunteers. The results show a significant reduction in the visible numbers of mast cells and the appearance of degranulated mast cells ghosts in the skin six hours after capsaicin application. Since capsaicin itself does not release Hi from mast cells, these data suggest that capsaicin-induced release of peptides from neurones could cause mast cell degranulation.