地骨皮甲素调节VEGF信号通路对分泌性中耳炎大鼠的作用研究

Kukoamine A regulating VEGF signal pathway in rats with otitis media with effusion

目的研究地骨皮甲素对分泌性中耳炎大鼠的作用及机制。方法72只大鼠随机分为6组,分别为对照组,模型组,地骨皮甲素低、中、高剂量组及泼尼松组,除对照组外,其余各组采用注射卵清蛋白的方法建立分泌性中耳炎大鼠模型,造模完成后,对照组及模型组灌胃给予生理盐水,地骨皮甲素低、中、高剂量组按照20 ml/kg分别灌胃给予大鼠0.5 mg/ml、1 mg/ml、2 mg/ml的地骨皮甲素,泼尼松组按照20 ml/kg灌胃给予大鼠0.25 mg/ml的泼尼松,连续给药21 d后,测定大鼠中耳灌洗液中IFN-γ、IL-4水平,血清TNF-α、IL-6及IL-1β水平,苏木精-伊红染色对大鼠中耳组织进行病理学检查,Western blot检测大鼠中耳组织VEGF、VEGFR-2水平。结果与模型组比较,地骨皮甲素各剂量组及泼尼松组大鼠血清TNF-α、IL-6及IL-1β水平,中耳灌洗液中IL-4水平均显著降低(P<0.05),而中耳灌洗液中IFN-γ水平显著升高(P<0.05),且与地骨皮甲素的剂量呈依赖性;病理学检查结果表明,与模型组比较,地骨皮甲素低、中剂量组分泌性中耳炎大鼠中耳黏膜肿胀情况好转,黏膜细胞脱落少见,地骨皮甲素高剂量组中耳黏膜较完整,细胞肿胀明显好转,偶见黏膜细胞脱落,泼尼松组分泌性中耳炎大鼠黏膜增厚基本消失,偶见细胞肿胀;Western blot结果表明,与模型组比较,地骨皮甲素各剂量组及泼尼松组大鼠中耳黏膜VEGF及VEGFR-2水平均显著降低(P<0.05),且与地骨皮甲素的剂量呈一定的依赖性。结论地骨皮甲素能够缓解分泌性中耳炎大鼠的疾病状态,改善大鼠疾病转归,其作用机制可能与其调节VEGF信号通路有关。

Objective To study the effect and mechanism of Kukoamine A on otitis media with effusion(OME)in rats.Methods A total of 72 rats were randomly divided into 6 groups:control group,model group,and low-,middle-and high-dose kukoamine A group and prednisone group.The rat model of OME was established by injection of ovalbumin in the groups except control group.After the establishment of the model,the control group and the model group were intragastrically given normal saline.The rats in the low-middle-and high-dose groups were given 0.5 mg/ml,1 mg/ml and 2 mg/ml of kukoamine A respectively according to 20 ml/kg,and the prednisone group was given prednisone by intragastric administration of 0.25 mg/ml in the prednisone group according to 20 ml/kg.After 21 days of continuous administration,the levels of IFN-γ,IL-4,serum TNF-α,IL-6 and IL-1β in middle ear lavage fluid were measured,and hematoxylin-eosin staining was used to examine the middle ear tissue of rats.The levels of VEGF and VEGFR-2 in middle ear tissue of rats were detected by Western blot.Results Compared with the model group,the levels of serum TNF-α,IL-6 and IL-1β and the level of IL-4 in middle ear lavage fluid in each dose group and prednisone group were significantly lower than those in the model group(P<0.05),while the level of IFN-γ in middle ear lavage fluid increased significantly(P<0.05),and it was dependent on the dose of Kukoamine A.The results of pathological examination showed that compared with the model group,the swelling of middle ear mucosa of rats with secretory otitis media in the low-and middle-dose groups was improved,and the exfoliation of mucosal cells was rare.The middle ear mucosa in the high-dose group was more complete;the swelling of cells was improved obviously,and occasionally the mucosal cells exfoliated.In the prednisone group,the mucosal thickening of OME practically disappeared,and occasionally the cells swelled.The results of Western blot showed that compared with the model group,the levels of VEGF and VEGFR-2 in middle ear mucosa of rats in each dose group and prednisone group were significantly lower(P<0.05),and it was dependent on the dose of kukoamine to some extent.Conclusion Kukoamine A can alleviate the disease state and improve the prognosis of OME,and its mechanism may be related to its regulation of VEGF signaling pathway.