RBL-2H3细胞脱颗粒模型评价注射用丹参多酚酸的安全性

目的 通过RBL-2H3肥大细胞脱颗粒模型考察注射用丹参多酚酸及丹参多酚酸B、D的致敏性。方法 RBL-2H3肥大细胞分为对照（PBS）组、C48/80 （阳性对照,4 mg/mL）组和梯度浓度（0.025、0.050、0.100、0.200、0.400、0.800 mg/mL）的注射用丹参多酚酸、丹参多酚酸B、丹参多酚酸D组,孵育30 min后,通过中性红染色试验观察脱颗粒现象,化学荧光法测定组胺释放率,酶联免疫吸附（ELISA）法测定β-氨基己糖苷酶释放率、类胰蛋白酶释放量。结果 与对照组比较,阳性药C48/80组、质量浓度≥0.2 mg/mL的丹参多酚酸B组、质量浓度≥0.4 mg/mL的丹参多酚酸D组、质量浓度为0.8 mg/mL的注射用丹参多酚酸组的细胞脱颗粒度显著升高（P<0.01、0.05）;注射用丹参多酚酸没有引起RBL-2H3细胞组胺释放率增加,C48/80组、质量浓度≥0.025 mg/mL的丹参多酚酸D组、0.8 mg/mL的丹参多酚酸B组组胺释放率即显著升高（P<0.001、0.05）;注射用丹参多酚酸和丹参多酚酸B组类胰蛋白酶释放量无显著性差异,质量浓度≥0.025 mg/mL的丹参多酚酸D组类胰蛋白酶释放量显著增加（P<0.001）;注射用丹参多酚酸没有引起β-氨基己糖苷酶释放率增加,0.8 mg/mL的丹参多酚酸D组、质量浓度≥0.1 mg/mL的丹参多酚酸B组的β-氨基己糖苷酶释放率显著增加（P<0.001）。结论 注射用丹参多酚酸在致敏性方面有较好的安全性。     

聚山梨酯80刺激肥大细胞RBL-2H3脱颗粒作用的评价

目的：研究不同类别及厂家的聚山梨酯80直接刺激肥大细胞RBL-2H3脱颗粒的作用,为建立完善的注射用辅料引发类过敏反应的筛选评价体系提供依据。方法：以不同剂量的聚山梨酯80处理RBL-2H3细胞,测定β-氨基己糖苷酶释放量,并通过MTT法进一步研究有脱颗粒作用的受试物对RBL-2H3细胞的毒性作用。结果：8种聚山梨酯80样品具有不同程度的直接刺激RBL-2H3细胞脱颗粒的作用,且呈浓度依赖性,其中上海试剂采购供应站提供的受试物作用极强,威尔制药口服级受试物作用较强,威尔制药A、威尔制药B、威尔制药注射级、威尔制药4个受试物作用相近,2个进口品种的作用略弱。在产生直接刺激RBL-2H3细胞脱颗粒作用的浓度下,上海试剂采购供应站的聚山梨酯80有明显的细胞毒性,并呈浓度依赖性。结论：聚山梨酯80能够直接刺激RBL-2H3细胞脱颗粒,其作用强度不同反映了产品的质量差异;上海试剂采购供应站提供的聚山梨酯80直接刺激RBL-2H3细胞脱颗粒的作用可能由其细胞毒性引起。     

绿原酸致RBL-2H3细胞脱颗粒反应及机制研究

目的 研究绿原酸对大鼠嗜碱性白血病细胞 RBL-2H3 脱颗粒作用及可能机制。方法 将不同质量浓度(3.125、6.250、12.500、25.000、50.000、100.000、200.000 μg·mL-1)的绿原酸作用于 RBL-2H3 细胞,通过实时细胞分析(RTCA)系统检测绿原酸干预后引起的细胞指数(CI)值变化,以评价 RBL-2H3 细胞脱颗粒情况;利用甲苯胺蓝染色观察细胞形态变化;化学荧光法测定组胺释放率;底物显色法测定β-氨基己糖苷酶释放率、类胰蛋白酶释放量;网络药理学预测绿原酸诱导RBL-2H3 细胞脱颗粒的潜在机制,并应用实时荧光定量PCR(qRT-PCR)对预测通路的主要靶点细胞外调节蛋白激酶(ERK1)、c-Jun氨基末端激酶(JNK)、p38丝裂原活化蛋白激酶(MAPK)mRNA水平进行检测。结果 绿原酸质量浓度 ≥ 6.25 μg·mL^-1时,可使RBL-2H3细胞的CI值在给药20min后呈现先快速上升后下降的趋势;绿原酸质量浓度 ≥ 12.5 μg·mL^-1时,RBL-2H3 细胞逐渐变圆甚至呈现多边形;与对照组比较,β-氨基己糖苷酶、组胺和类胰蛋白酶的释放量显著增加(P<0.05、0.01、0.001)。网络药理学预测发现,绿原酸致细胞脱颗粒作用可能与MAPK、磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(Akt)等信号通路相关;qRT-PCR 结果证实,与对照组比较,绿原酸可显著增加 ERK1、p38MAPK mRNA表达(P<0.05、0.01),但对JNK mRNA表达影响不显著。结论 绿原酸可通过激活ERK1、p38 MAPK通路诱导 RBL-2H3 细胞发生脱颗粒,具有潜在的诱发类过敏反应作用。     

RBL-2H3细胞不适合用于类过敏模型的建立

目的考察RBL-2H3细胞是否适用于建立类过敏反应模型。方法用荧光定量聚合酶链反应考察RBL-2H3细胞上Mas相关G蛋白偶联受体(Mas-related G protein cou-pled receptor,Mrgpr)B2的表达情况;用显微镜观察和MTS法考察Compound 48/80对RBL-2H3细胞活力的影响;测定不同浓度Compound 48/80刺激RBL-2H3细胞脱颗粒释放的β-己糖胺酶含量,对比RBL-2H3细胞、人肥大细胞系LAD2和大鼠腹腔肥大细胞(rat peritoneal mast cells,RPMCs)对Compound 48/80响应性的差异。结果RBL-2H3细胞可表达MrgprB2受体。Compound 48/80能剂量依赖性地诱导RBL-2H3细胞释放β-己糖胺酶,但在高剂量(≥20 mg·L^-1)时对RBL-2H3的细胞活力产生明显影响,此时释放的β-己糖胺酶应当是由于其细胞毒作用引起细胞破裂所致。同在无毒剂量(10 mg·L^-1)的Compound 48/80刺激下,LAD2和RPMCs的响应性良好,β-己糖胺酶释放量分别为空白对照的15.02倍和16.05倍,而RBL-2H3细胞仅为空白对照的2.35倍。结论RBL-2H3细胞对Compound 48/80的响应性差,表明其并不适用于建立类过敏反应模型。     

聚山梨酯80对多源肥大细胞脱颗粒的影响研究

目的 通过比较不同浓度聚山梨酯80溶液对RBL-2H3、P815、Ku812细胞脱颗粒的影响,探究聚山梨酯80的量与过敏反应的关系,进而筛选出一套灵敏、稳定的体外肥大细胞脱颗粒模型。方法 体外培养RBL-2H3、P815和Ku812细胞,测定3株细胞的生长曲线,在细胞生长对数期,以不同浓度（0.04、0.20、1.00、5.00、10.00、20.00、40.00、80.00 mg/mL）聚山梨酯80分别刺激3株细胞,采用中性红染色法显微镜下观察不同浓度聚山梨酯80溶液对3株细胞脱颗粒的影响,并计算脱颗粒百分率,同时以化学发光法分别检测组胺和β-氨基己糖苷酶释放率,以酶联免疫吸附法测定类胰蛋白酶的释放量;并进一步检测聚山梨酯80对人的肥大细胞IgE释放的影响。结果 3株肥大细胞脱颗粒模型中,各细胞的脱颗粒指标均随聚山梨酯80浓度的升高而升高。相同浓度聚山梨酯80对人源、大鼠、小鼠肥大细胞的类胰蛋白酶释放量无较大统计学差异;与RBL-2H3细胞系比较,P815细胞和组胺释放率显著降低（P<0.05、0.01）,Ku812细胞组胺释放率和β-氨基己糖苷酶释放率显著升高（P<0.05、0.01）,Ku812细胞脱颗粒最灵敏。但在实验过程中发现Ku812细胞模型稳定性、可重复性较差,而RBL-2H3细胞稳定性、可重复性均优于Ku812和P815细胞。0.04~80.00 mg/mL的聚山梨酯80溶液作用于Ku812细胞产生的IgE均低于检测限。结论 聚山梨酯80诱导的过敏反应可能是不经过IgE介导的类过敏反应,随着聚山梨酯80浓度的增大,3个细胞模型脱颗粒现象显著,相比于Ku812和P815细胞,RBL-2H3细胞更适合作为体外肥大细胞脱颗粒检测模型。     

聚山梨酯-80致RBL-2H3肥大细胞脱颗粒的研究

目的:研究聚山梨酯-80对RBL-2H3肥大细胞脱颗粒释放组胺的影响.方法:培养大鼠来源的RBL-2H3肥大细胞,取不同厂家来源的聚山梨酯-80与RBL-2H3细胞共培养60 min,用荧光分光光度法定量检测RBL-2H3细胞释放的组胺量,计算组胺释放率.结果:不同厂家来源的聚山梨酯-80与RBL-2H3细胞作用60 min后,细胞的组胺释放率与空白对照组相比均显著增加,在一定浓度范围内,组胺的释放随聚山梨酯-80浓度的增加而增加.结论:聚山梨酯-80可导致RBL-2H3肥大细胞脱颗粒,并存在着明显的量效关系,为研究聚山梨酯80致过敏反应机制提供了一定的依据.     

血必净注射液及其成分对肥大细胞脱颗粒作用的影响

目的：研究血必净注射液及其含有的10种化合物对P815细胞脱颗粒、组胺和氨基己糖苷酶释放的影响。方法：选取P815细胞作为体外过敏模型,通过CCK-8法测定各组分的IC10作为给药浓度,C48/80作为阳性药,采用中性红染色,计算出各组脱颗粒百分率;采用ELISA法测定各组分上清液中组胺的释放量;采用底物法检测各组上清液中氨基己糖苷酶的释放度。结果：与空白组相比,绿原酸、蒿本内酯、咖啡酸、丹酚酸B和血必净组细胞的脱颗粒百分率存在极显著差异;绿原酸、咖啡酸对组胺释放量的影响最大,且显著增加细胞中的氨基己糖苷酶释放量。结论：血必净注射液会刺激P815细胞释放过敏相关物质,该反应很可能与其含有的绿原酸、咖啡酸、原儿茶醛、蒿本内酯和丹酚酸B等成分有关。     

N—（3′，4′，5′—三甲氧基肉桂酰）邻氨基苯甲酸对抗原诱发的离体豚鼠回肠收缩、大鼠肥大细胞脱颗粒及组胺释放的影响

实验证明N－（3′，4′，5′－三甲氧基肉桂酰）邻氨基苯甲酸（TOA）管内浓度80μg/ml能明显抑制抗原诱发的主动致敏豚鼠离体回肠收缩。TOA管内浓度25和50μg/ml能显著抑制亲同种细胞抗体介导的大鼠肠系膜肥大细胞脱颗粒和腹腔肥大细胞组胺释放。     

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.     

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。     

不同产地紫花地丁中总黄酮与微量元素的含量测定

目的: 对不同产地紫花地丁中总黄酮和微量元素的含量进行了研究, 为后期紫花地丁物质基础研究奠定基础。方法: 用超声波提取法提取紫花地丁中的总黄酮, 采用紫外分光光度法, 在509 nm处测定总黄酮含量;紫花地丁药材经微波消解后, 以锗、铟、铋为内标, 用电感耦合质谱法(ICP-MS)测定微量元素含量。结果: 测定了十个产地紫花地丁中总黄酮的含量, 其中河北安国和陕西的含量较高, 分别为2.363%和2.052%。各产地微量元素的含量大小基本符合:钙 > 锰 > 铜 > 锌 > 铅 > 铬 > 砷 > 镉 > 汞。结论: 黄酮含量差异可能与环境有关, 而微量元素的富集自身因素占主要地位。     

β‐eudesmol suppresses allergic reactions via inhibiting mast cell degranulation

The regulatory effect of β‐eudesmol, which is an active constituent of Pyeongwee‐San (KMP6), is evaluated for allergic reactions induced by mast cell degranulation. Phorbol 12‐myristate 13‐acetate (PMA) plus calcium ionophore A23187‐stimulated human mast cell line, HMC‐1 cells, and compound 48/80‐stimulated rat peritoneal mast cells (RPMCs) are used as the in vitro models; mice models of systemic anaphylaxis, ear swelling, and IgE‐dependent passive cutaneous anaphylaxis (PCA) are used as the in vivo allergic models. The results demonstrate that β‐eudesmol suppressed the histamine and tryptase releases from the PMA plus calcium ionophore A23187‐stimulated HMC‐1 cells. β‐eudesmol inhibits the expression and activity of histidine decarboxylase in the activated HMC‐1 cells. In addition, β‐eudesmol inhibits the levels of histamine and tryptase released from the compound 48/80‐stimulated RPMCs. Furthermore, β‐eudesmol decreases the intracellular calcium level in the activated RPMCs. β‐eudesmol also decreases the compound 48/80‐induced mortality and ear swelling response. β‐eudesmol suppresses the serum levels of histamine, IgE, interleukin (IL)‐1β, IL‐4, IL‐5, IL‐6, IL‐13, and vascular endothelial growth factor (VEGF) under PCA mice as well as PCA reactions. Therefore, the results from this study indicate the potential of β‐eudesmol as an anti‐allergic drug with respect to its pharmacological properties against mast cell‐mediated allergic reactions.     

响应面法优化CO2超临界萃取紫花地丁总黄酮的工艺研究

目的采用C02超临界萃取技术,优化从紫花地丁中萃取总黄酮的工艺条件。方法采用紫外可见分光光度法测定总黄酮含量,以总黄酮萃取率为指标,通过响应面法考察工艺条件。结果最佳工艺条件为：萃取压力35MPa、萃取温度54℃、夹带剂流速0．48mL·min^-1,乙醇浓度80％,萃取时间120min,实际总黄酮萃取率为5．89％。对萃取率影响最大的因素是萃取压力和萃取温度。结论C02超临界流体萃取紫花地丁总黄酮得率高,溶剂用量少,工序简单可行。     

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。     

参麦注射液致RBL-2H3细胞脱颗粒的研究

目的 探讨参麦注射液(SMI)对RBL-2H3细胞脱颗粒的影响及其原因。方法 以C48/80为工具药建立RBL-2H3细胞脱颗粒模型, 检测不同浓度C48/80与RBL-2H3细胞作用不同时间后细胞β-己糖苷酶、类胰蛋白酶和组胺的释放率以及细胞活力, 在细胞活力大于80%情况下, 选择释放程度较高的指标和条件为优选考察指标和条件。将SMI和其溶剂(Tween-80)原液等比稀释成不同浓度后与RBL-2H3细胞共同培养, 通过中性红染色法观察细胞脱颗粒的形态学变化, 分别用显色法和间接荧光法检测细胞上清的β-己糖苷酶和组胺释放率, 采用细胞计数法(CCK-8)检测细胞的活力。结果 RBL-2H3细胞脱颗粒模型的最佳作用时间为30 min, 最佳指标为β-己糖苷酶和组胺释放率。与空白组相比, SMI质量浓度低于13.3 g生药/L(3倍临床浓度)时, 细胞中性红染色未见脱颗粒现象, 组胺和β-己糖苷酶释放率亦无差异;而在Tween-80质量浓度为1.00 g/L时, SMI 40 g生药/L(9倍临床浓度)组和溶剂1.00 g/L组细胞中性红染色均可见脱颗粒现象, 细胞上清组胺和β-己糖苷酶释放率亦明显增加。此外, CCK-8结果显示, 与空白组相比, 各浓度的SMI对细胞活力均无影响。结论 SMI低于3倍临床浓度无明显RBL-2H3细胞脱颗粒作用;而在9倍临床浓度能刺激细胞脱颗粒, 这种脱颗粒作用可能与所含溶剂(Tween-80)有关, 与其对RBL-2H3的细胞毒性作用无关。提示SMI在低于3倍临床浓度相对安全, 在9倍临床浓度时有致类过敏反应的风险。     

Anti-allergic activity of emodin on IgE-mediated activation in RBL-2H3 cells

BackgroundEmodin (1,3,8-trihydroxy-6-methylanthraquinone) is a Chinese herbal anthraquinone derivative from the rhizome of rhubarb (Rheum palmatum L.) that exhibits numerous biological activities, such as antitumor, antibacterial, antiinflammatory, and immunosuppressive. In the present studies, the anti-allergic activities of emodin were investigated to elucidate the underlying active mechanisms.MethodsThe inhibitory effects of emodin on the IgE-mediated allergic response in rat basophilic leukemia (RBL-2H3) cells were evaluated by measuring the release of granules and cytokines. The Ca²⁺ mobilization in RBL-2H3 cells loaded with the Ca²⁺-reactive fluorescent probe Fluo-4 AM was also measured by laser scanning confocal microscope.ResultsEmodin inhibited the release of β-hexosaminidase (β-HEX; IC₅₀ = 5.5 μM) and tumor necrosis factor (TNF)-α (IC₅₀ = 11.5 μM) from RBL-2H3 cells induced by 2,4-dinitrophenylated bovine serum albumin (DNP-BSA) and displayed stronger inhibition of β-HEX release than ketotifen fumarate salt (IC₅₀ = 63.8 μM). Emodin at a concentration of 12.5 μM also inhibited the DNP-BSA-induced influx of extracellular Ca²⁺ in RBL-2H3 cells.ConclusionsThese results suggested that emodin likely exhibits anti-allergic activities via increasing the stability of the cell membrane and inhibiting extracellular Ca²⁺ influx.     

Spirodela polyrhiza extract modulates the activation of atopic dermatitis-related ion channels,Orai1 and TRPV3, and inhibits mast cell degranulation

Context: Spirodela polyrhiza (L.) Schleid. (Lemnaceae), Spirodelae Herba (SH), has been known to relieve inflammation, urticaria and skin symptoms including pruritus, eczema and rash.

Objective: The effects of SH extract on two calcium ion channels, Orai1 and TRPV3, and their potential as novel therapeutics for atopic dermatitis (AD) were investigated. The regulatory role of Orai1 on mast cell degranulation was evaluated.

Materials and methods: The dried leaves of SH were extracted by 70% methanol. Effects of SH extract (100?μg/mL) in an HEK293T cell line overexpressing human Orai1 or TRPV3 were assessed. Ion channel modulation in transfected HEK293T cells was measured using a conventional whole-cell patch-clamp technique. IgE-antigen complex-stimulated mast cell degranulation was measured by β-hexosaminidase assay with morphological observation after treatment with 20, 50 and 100?μg/mL SH extract.

Results: SH extract (100?μg/mL) significantly inhibited Orai1 activity (63.8?±?0.97%) in Orai1-STIM1 co-overexpressed HEK293T cells. SH extract significantly increased TRPV3 activity (81.29?±?0.05% at ?100?mV) compared with the positive control 2-APB (100?μM), which induced full activation. SH extract inhibited degranulation in IgE-antigen complex-stimulated RBL-2H3 mast cells by decreasing β-hexosaminidase activity (3.14?±?0.03, 2.56?±?0.12 and 2.29?±?0.08?mU/mg, respectively).

Conclusion: Our results suggested that SH extract could treat abnormal skin barrier pathologies in AD through modulation of the activities of the calcium ion channels Orai1 and TRPV3 and inhibition of mast cell degranulation. This is the first report of an herbal effect on the modulation of ion channels associated with skin barrier disruption in AD pathogenesis.     

甘草酸铵调控IL-33/ST2通路对特应性皮炎小鼠肥大细胞活化的影响

目的 研究甘草酸铵对特应性皮炎（AD）小鼠IL-33/ST2通路及肥大细胞的活化情况的影响。方法 72只ICR小鼠（雌雄各半）随机均分为对照组、模型组及甘草酸铵低、中、高剂量（25、50、100 mg/kg）和泼尼松龙（阳性药,60 mg/kg）组。除对照组外,以丙酮-DNCB为致敏源构建AD小鼠模型,建模后各组ip相应药物,对照组和模型组ip生理盐水。记录小鼠夜间搔抓次数;甲苯胺蓝患处皮肤组织染色法观察肥大细胞活化情况;ELISA法检测白细胞介素（IL）-33和ST2血清学水平;实时荧光定量PCR（qRT-PCR）和Weston blotting法检测皮肤组织中的IL-33和ST2 mRNA和蛋白水平。结果 与对照组比较,模型组小鼠的搔抓次数显著增多（P<0.05）,肥大细胞密度显著升高（P<0.05）,IL-33和ST2的血清学水平、皮肤组织的转录水平和蛋白表达水平均显著升高（P<0.05）;与模型组比较,泼尼松龙组和甘草酸铵低、中、高剂量组的搔抓次数和肥大细胞密度分别显著减少和降低（P<0.05）,IL-33、ST2的血清学水平、皮肤组织mRNA和蛋白表达均显著降低（P<0.05）。结论 甘草酸铵能够明显抑制AD模型小鼠IL-33和ST2的血清学水平、皮肤组织中的转录水平和蛋白表达,降低了肥大细胞的活化程度,从而减轻AD的瘙痒症状。     

Effects of C18 Fatty Acids on Intracellular Ca2+ Mobilization and Histamine Release in RBL-2H3 Cells

To investigate the underlying mechanisms of C18 fatty acids (stearic acid, oleic acid, linoleic acid and α-linolenic acid) on mast cells, we measured the effect of C18 fatty acids on intracellular Ca²⁺ mobilization and histamine release in RBL-2H3 mast cells. Stearic acid rapidly increased initial peak of intracellular Ca²⁺ mobilization, whereas linoleic acid and α-linolenic acid gradually increased this mobilization. In the absence of extracellular Ca²⁺, stearic acid (100 µM) did not cause any increase of intracellular Ca²⁺ mobilization. Both linoleic acid and α-linolenic acid increased intracellular Ca²⁺ mobilization, but the increase was smaller than that in the presence of extracellular Ca²⁺. These results suggest that C18 fatty acid-induced intracellular Ca²⁺ mobilization is mainly dependent on extracellular Ca²⁺ influx. Verapamil dose-dependently inhibited stearic acid-induced intracellular Ca²⁺ mobilization, but did not affect both linoleic acid and α-linolenic acid-induced intracellular Ca²⁺ mobilization. These data suggest that the underlying mechanism of stearic acid, linoleic acid and α-linolenic acid on intracellular Ca²⁺ mobilization may differ. Linoleic acid and α-linolenic acid significantly increased histamine release. Linoleic acid (C18:2: ω-6)-induced intracellular Ca²⁺ mobilization and histamine release were more prominent than α-linolenic acid (C18:3: ω-3). These data support the view that the intake of more α-linolenic acid than linoleic acid is useful in preventing inflammation.