明胶海绵和透明质酸在地塞米松圆窗灌注中对豚鼠圆窗膜形态及功能的影响

目的圆窗分别放置明胶海绵与透明质酸,观察地塞米松圆窗灌注对豚鼠圆窗膜形态及功能影响。方法①36只豚鼠随机分为3组,Ⅰ组圆窗龛放置明胶海绵并在圆窗置管;Ⅱ组圆窗龛放置含2%透明质酸明胶海绵置管,Ⅲ组圆窗龛放置明胶海绵置管,Ⅱ组和Ⅲ组经圆窗置管向圆窗灌注地塞米松7d后。用光学显微镜和扫描电镜观察圆窗膜变化。36只豚鼠中随机取6只左耳作为正常对照（Ⅳ组）。②另取18只豚鼠,按给药时间分为1、4、7d3组,每组各取3只分为实验组和对照组,实验组圆窗放置透明质酸明胶海绵,对照组圆窗放置明胶海绵。各组经圆窗置管圆窗灌注地塞米松后,用LC-6A高效液相色谱仪测定外淋巴液中地塞米松浓度。结果光镜和扫描电镜检查发现Ⅰ、Ⅱ和Ⅲ组圆窗膜厚度和形态与正常对照Ⅳ组比较无明显差异（P〉0.05）;圆窗放置透明质酸明胶海绵后豚鼠外淋巴液中地塞米松含量明显高于明胶海绵组（P〈0.01）。结论①圆窗放置明胶海绵和透明质酸对豚鼠圆窗膜形态无明显影响。②透明质酸明胶海绵能提高地塞米松的圆窗膜通透性。

Morphologic and functional study of round window membrane after administration of gelfoam and hyaluronic acid with intratympanic dexamethasone perfusion in guinea pig

Objective To observe the morphologic and functional changes of round window membrane in guinea pigs after administration of gelfoam and hyaluronic acid with intratympanic dexamethasone perfusion.Methods ① Thirty-six healthy male guinea pigs were divided randomly into three groups;a pipe was introduced into the round window in all animals.Gelfoam was placed in round window niche in group I and group III.Gelfoam soaked with hyaluronic acid was placed in group Ⅱ.Dexamethasone was perfused through the pipe once a day for 7 days in group Ⅱ and group Ⅲ.The animals were sacrificed and the temporal bones were harvested at 1 day or 7 days after dexamethasone perfusion finished.The morphologic changes of round window membrane were studied with both light microscope and scanning electron microscope.② Eighteen guinea pigs were divided into three groups according to the course of dexamethasone administration;Dexamethasone was perfused through the pipe once a day for 1,4,7 days respectively.Each group was then subdivideded into the experimental group and control group.Gelfoam alone and gelfoam with hyaluronic acid were placed in round window niche in the control group and experimental group respectively.The perilymph of the scala tympani was collected and the concentration of dexamethasone in the samples was assayed by HPLC.Results Under light microscope and scanning electron microscope,no significant changes were found in the thickness and morphology of round window membrane of guinea pigs between group Ⅰ,Ⅱ,Ⅲ and the control group.The concentration of dexamethasone in the perilymph of the experimental group was higher than that of the control group.Conclusion Gelfoam and hyaluronic acid cause statistical insignificant morphological changes of round window membrane but can improve the penetration of dexamethasone through round window membrane.