Eriksson P O, Hellström S
Department of Clinical Sciences, Otorhinolaryngology, University Hospital of Northern Sweden, Umeå, Sweden.
Laryngoscope. 2001 Jul;111(7):1264-70. doi: 10.1097/00005537-200107000-00023.
The pars flaccida is extremely rich in mast cells. On stimulation the mast cells release preformed and de novo synthesized inflammatory substances. The purpose of this study was to examine how these mast cell substances provoke inflammatory changes in the tympanic membrane.
In vivo, murine model.
In a rat model, the mast cell secretagogue compound 48/80 was applied locally to the tympanic membrane on 4 consecutive days and the ensuing inflammatory changes were evaluated by otological, light, and electron microscopy 3, 6, 9, 12, 18, 24, 36, and 48 hours and 4, 6, and 8 days later.
Degranulation of the mast cells occurred within 3 hours of applying compound 48/80. Release of the mast cell substances coincided with an inflammatory event characterized by a two-stage reaction: an edema stage, peaking 6 hours after application, followed by a massive invasion of inflammatory cells, peaking at 24 and 48 hours. Pars flaccida and pars tensa were both involved, pars flaccida showing the earliest changes. Pars tensa exhibited the same biphasic reaction as pars flaccida, but approximately 6 hours later.
The mast cells of the pars flaccida have the capacity to elicit an intense inflammation of the tympanic membrane. The biphasic reaction pattern resembles that observed in experimental otitis media, suggesting involvement of the mast cells in this inflammatory condition of the middle ear.
松弛部富含肥大细胞。受到刺激时，肥大细胞会释放预先形成的和新合成的炎症物质。本研究的目的是探讨这些肥大细胞物质如何引发鼓膜的炎症变化。
体内小鼠模型。
在大鼠模型中，连续4天局部向鼓膜应用肥大细胞促分泌剂化合物48/80，并在3、6、9、12、18、24、36和48小时以及4、6和8天后，通过耳科检查、光学显微镜和电子显微镜评估随后发生的炎症变化。
应用化合物48/80后3小时内肥大细胞发生脱颗粒。肥大细胞物质的释放与以两阶段反应为特征的炎症事件同时发生：水肿阶段，在应用后6小时达到峰值，随后炎症细胞大量浸润，在24和48小时达到峰值。松弛部和紧张部均受累，松弛部显示出最早的变化。紧张部与松弛部表现出相同的双相反应，但大约晚6小时。
松弛部的肥大细胞有能力引发鼓膜的强烈炎症。这种双相反应模式类似于在实验性中耳炎中观察到的模式，表明肥大细胞参与了中耳的这种炎症状态。
