灌胃左旋甲状腺素(L-T_(4))对妊娠小鼠胎盘中DIO3基因表达及胚胎数的影响  

Effects of Levothyroxine(L-T_(4))by Gavage on DIO3 Expression in Mice Placenta and Embryo Number

作　　者：赵娟 李立煊 陈雯敏 肖金龙 仲涛 ZHAO Juan;LI Lixuan;CHEN Wenmin;XIAO Jinlong;ZHONG Tao(Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China)

机构地区：[1]四川农业大学畜禽遗传资源发掘与创新利用四川省重点实验室,成都611130

出　　处：《畜牧兽医学报》2022年第1期122-131,共10页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：四川省大学生创新创业训练计划项目(201710626093)。

摘　　要：旨在探究小鼠胚胎发育过程中DIO3的表达模式和灌胃左旋甲状腺素(L-T_(4))对孕鼠胎盘中DIO3基因表达和胚胎数的影响,以期为研究妊娠期母体甲状腺激素异常提供基础数据。本研究以6周龄健康昆明小鼠(雌鼠70只,雄鼠35只)为试验对象。雌鼠经适应性饲养1周后,腹腔灌胃10 U PMSG(溶于0.3 mL生理盐水),正常饲喂48 h后将雄鼠和雌鼠以1∶2的比例合笼过夜。次日清晨对雌鼠进行阴道检测,若阴道处可见乳白色阴栓则视为妊娠第1天。将妊娠小鼠随机分为5组,试验组小鼠分别灌胃0.25(SG,n=10)、1.25(MG,n=10)、2.50(LG,n=10)和5.00μg·μL^(-1)(HG,n=10)的L-T_(4),对照组小鼠给予等量生理盐水(CG,n=10),每天灌胃80μL,持续10 d。采集试验组妊娠天数分别为第10和18天的小鼠胎盘(n=4/组)并记录胚胎数。此外,采集对照组第10、14和18天的胎盘及未妊娠小鼠卵巢(n=3/组)。利用RT-qPCR、原位杂交和免疫组化技术检测小鼠胎盘组织中DIO3的表达情况,利用化学发光仪检测妊娠小鼠灌胃L-T_(4)后血清中TSH、FT_(3)和FT_(4)的含量变化。RT-qPCR结果表明,在正常生理条件下,胎盘组织中DIO3的表达水平随妊娠时间增长呈递减趋势,在妊娠期第10天时表达量最高,在第18天时表达量最低,且低于未妊娠时的表达量(P<0.01)。石蜡切片显色原位杂交及免疫组化分析与RT-qPCR结果一致。灌胃L-T_(4)后,母鼠体内血清TSH、FT_(3)和FT_(4)水平均随灌胃浓度的增加呈现升高趋势,且各处理组间差异显著(P<0.05)。此外,DIO3的表达随灌胃剂量的增加而增加。妊娠第10天,DIO3的表达量在对照组与HG组之间呈极显著差异(P<0.01),对照组与SG组、MG组和LG组之间无显著差异。妊娠第18天,对照组DIO3的表达量显著高于灌胃组(P<0.01)。妊娠第10天灌胃组妊娠母鼠胚胎数量略大于对照组,但差异不显著;妊娠第18天灌胃组和对照组妊娠母鼠胚胎数量大致相同。综上所述,�The aim of this study was to investigate the expression pattern of DIO3 during the embryonic development in mice,assess the effects of intragastric gavage of levothyroxine(L-T_(4))on DIO3 expression and embryo number,and provide basic data for the study of maternal thyroid hormone abnormalities during pregnancy.In this study,the healthy Kunming mice(70 females,35 males)aged 6 weeks were used as experimental objects.After adaptive feeding for one week,female mice were given intraperitoneal intragastric administration of 10 U PMSG(dissolved in 0.3 mL normal saline).After normal feeding for 48 h,male and female mice were caged together at the ratio of 1∶2 overnight.Once the milky vaginal suppository was visible in the morning of the next day,it was considered as the first day of pregnancy.Pregnant mice were randomly divided into 5 groups.The mice in experimental groups were intragastric administrated with 0.25(SG,n=10),1.25(MG,n=10),2.50(LG,n=10)and 5.00μg·μL^(-1)(HG,n=10)of L-T_(4),re-spectively,and the control group was intragastric administrated with the same amount of normal saline(CG,n=10),80μL per day for 10 days.Placentas were collected from mice in exprmental groups on the 10th and 18th day of gestation(n=4/group)and the numbers of embryos were recorded.In addition,ovaries of non-pregnant mice and placentas of mice from the control group on the 10th,14th and 18th day of gestation(n=3/group)were collected.The expression of DIO3 in placentas of mice was detected by RT-qPCR,in situ hybridization and immunohistochemistry.The contents of TSH,FT_(3) and FT_(4)in serum of pregnant mice were detected by chemiluminescence meter after intragastric administration of L-T_(4).The results of RT-qPCR showed that,under normal physiological condition,the expression level of DIO3 in placenta decreased with the increase of gestation time,and the highest expression level was found on the 10th day of gestation,and the lowest expression level was found on the 18th day of gestation,which was lower than that in non-gestation(

关 键 词：小鼠 妊娠期 DIO3 基因表达 甲状腺激素 

分 类 号：S814[农业科学—畜牧学]