以形态与组织学为基础筛选诱导胎鼠腭裂的四氯二苯二噁英最适剂量

目的观察在不同四氯二苯二噁英(TCDD)剂量的作用下,胎鼠腭裂形成过程中的形态学、组织学变化,以筛选TCDD诱导腭裂模型的最适剂量。方法C57BL/6J孕鼠于妊娠第10天随机分为对照组和实验Ⅰ～Ⅳ组,每组6只;对照组以玉米油0.1ml灌胃,实验Ⅰ、Ⅱ、Ⅲ、Ⅳ组分别以TCDD32、28、24、20μg/kg灌胃。妊娠第17.5天处死孕鼠,称量孕鼠及胚胎体重,记录活胎鼠数、腭裂数、吸收胎及死胎鼠数。另取15只C57BL/6J孕鼠随机分组同前,处理方法同前;各组分别于妊娠第13.5、14.5和15.5天剪取胎鼠头部,解剖显微镜下观察;并行苏木精-伊红染色(HE染色),观察。结果各组孕鼠增加的体重及活胎鼠的体重差异均无显著性。Ⅰ、Ⅱ、Ⅲ组较对照组双侧腭突发育瘦小,上抬延迟;Ⅳ组双侧腭突发育及上抬与对照组相比无明显差异。Ⅰ～Ⅳ组胎鼠腭裂发生率分别为97.37%、93.02%、65.12%、56.82%,对照组未见胎鼠腭裂形成。结论 TCDD28μg/kg是建立C57BL/6J胎鼠腭裂模型的最适剂量。

Be based on the morphological and histological changes to study optimal dose of TCDD induced cleft palate in mice embryo

Objective To define the optimal 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD) dose based on the morphological and histological changes of fetal mice cleft palate induced by different TCDD doses.Methods The pregnant mice were randomly divided into five groups and 6 in each grouop,and were gavaged on gestation day 10(GD10).The control group were given 0.1ml corn oil,and the experimental groupsⅠ,Ⅱ,Ⅲ,Ⅳ were given 32,28,24,20μg/kg TCDD respectively.To weight pregnant mice and embryos,record the number of live,cleft palate,dead and resorption fetal mice on GD 17.5.Another 15 pregnant mice were randomly divided into five groups(same as above) and 3 in each group.The coronal sections of the fetal mice heads were prepared at GD 13.5,14.5 and 15.5 respectively,stained with haematoxylin-eosin staining(HE) and observed by microscopy.Results No significant differences in embryonic weight and live fetuses weight in each group.Compared with the control group,experimental groupsⅠ~Ⅲ had small palate shelves(PS) and delayed palae shelves lift;the palate development and elevation in experimental group Ⅳ was similar to the control group.The incidence of cleft palate in the experimental groups Ⅰ~Ⅳ were 97.37%,93.02%,65.12%,56.82%,and no cleft palate in the control group.Conclusion The optimal dose of TCDD to induce cleft palate in C57BL/6J mice is 28μg/kg.