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目的:观察还原型谷胱甘肽稳态的改变对腭中嵴上皮细胞形态及腭裂发生率的影响,探讨氧化自由基在四氯二苯二噁英(TCDD)致畸过程中的作用.方法:将GD10 的SPF 级C57BL/6J 孕鼠随机分为4 组,TCDD 组:腹腔注射生理盐水和TCDD 灌胃;TCDD+丁硫氨酸-亚砜胺(BSO)组:腹腔注射BSO 4 h 后给予TCDD 灌胃;BSO 组:腹腔注射BSO 和玉米油灌胃;对照组:腹腔注射生理盐水和玉米油灌胃.光学显微镜和电子扫描电镜下观察胎鼠腭胚突的发育及细胞表面形态.统计各组小鼠在GD17 的腭裂发生率.免疫组织化学方法检测各组腭中嵴上皮各时期CYP1A1 蛋白的表达.采用SPSS13.0 软件包对数据进行统计分析.结果:TCDD 成功构建高致畸率的腭裂模型.BSO 增加了5％的腭裂发生率,但是相对于TCDD 组无显著差异(P＞0.05).TCDD 组腭胚突上抬时间较对照组推迟1 d,添加BSO 的 TCDD 组腭胚突上抬过程较正常组减慢.电镜下胚胎发育的各发育时期,腭中嵴上皮表面TCDD 组与对照组有显著差异.免疫组织化学检测发现,TCDD 组腭中嵴上皮可见CYP1A1 高表达.结论:扰乱体内还原型谷胱甘肽稳态,可能会减少对小鼠体内氧化自由基的消耗,从而影响腭胚突的融合,继而加速了TCDD 的毒性,影响腭裂发生.“,”PURPOSE: To elucidate the impact of glutathione homeostasis in organogenesis stage embryos on 2,3,7,8-tetrachlorodibenzo -p -dioxin (TCDD) -induced cleft palate in fetal mice. METHODS: Pregnant C57BL/6J mice were randomly allocated to blank control group, TCDD exposed group, L-buthionine-sulfoximine (BSO)exposed group and BSO+TCDD exposed group. Each GD10 animal was weighted and treated with 0.1mL normal saline (for blank control group and TCDD exposed group) or 600 mg/kg BSO (for BSO group and TCDD+BSO group). After 4 hours, TCDD was orally administrated to subjects in both TCDD group and TCDD+BSO group, but corn oil was used as vehicle control for control group and BSO group. Fetal mice palates were imaged using light microscopy on GD13.5, GD14, GD14.25, GD14.5, GD14.75 and GD15; scanning electronmicroscopy was used on GD13.5, GD14.5, and GD15.5, and cleft palate were recorded on GD17.5. Three GD14.5 palate sections from each group were examined by immunohistochemistry. SPSS13.0 software package was used for statistical analysis. RESULTS: TCDD successfully induced cleft palate. BSO can increase 5％ of cleft palate. In the TCDD treated group, palatal shelves elevated 1 day later than in the control group. In the TCDD and BSO group, 0.25 day later than the TCDD group, all palates had elevated by GD 15.0. After elevation, the shelves contacted each other and fused. Under a high magnification (×2500), compared to the control group (GD14.5), TCDD group (GD 15), no filaments were observed and cell shapes were flat with unclear boundaries. The group treated with TCDD and BSO had no significant difference from the TCDD group in the end, but had temporal variations. The TCDD exposed group had a higher expression of CYP1A1 on the frontal epithelia than the control group. CONCLUSIONS: Breaking the balance of glutathione may decline the formation of filopodia and MEE motility due to reducing the consumption of reactive oxygen species, filopodia and MEE movement. This may result in accelerating the ultrastructure change of the palatal surface to a normal state, leading to a higher rate of cleft palate in TCDD-treated fetal mice.