孕早期大鼠剖宫取出胚胎后机械刮宫方法构建宫腔粘连模型

Establishment of intrauterine adhesion model by mechanical curettage after embryo removal by cesarean section in early pregnancy rats

目的采用孕早期大鼠剖宫取出胚胎后机械刮宫方法构建宫腔粘连(IUA)模型,并评价其功能。方法48只8~9周龄动情周期稳定的SD雌性大鼠,随机分为A、B、C、D组,每组12只,A、B、C组雌鼠与雄鼠和笼后筛选妊娠大鼠(记为妊娠第0.5天),于妊娠第5.5~6.5天采用孕早期大鼠剖宫取出胚胎后机械刮宫方法构建IUA模型,D组单独饲养不与雄鼠和笼,打开宫腔后即缝合并关腹,不刮宫。A、B、C组刮宫后继续饲养1、2、3个动情周期,各组处死6只大鼠,取子宫组织,HE染色后测算各组大鼠子宫内膜腺体数目,采用Masson染色法观察各组大鼠子宫内膜纤维化程度,采用免疫组化法检测子宫内膜组织TGF-β1。每组剩余6只大鼠随机与雄鼠和笼,于妊娠第14.5天处死孕鼠,记录双侧子宫内胚胎数目。结果与D组相比,A、B、C组大鼠子宫内膜腺体数目少、子宫内膜纤维化评分高、TGF-β1相对表达量高(P均<0.05);与B、C组相比,A组大鼠子宫内膜腺体数目多、纤维化评分低、TGF-β1相对表达量低(P均<0.05)。妊娠第14.5天A、B、C、D组大鼠双侧子宫胚胎数目分别为(2.08±1.16)、0、0、(6.75±1.14)个。与D组相比,A组大鼠双侧子宫胚胎数目少(P<0.05)。结论采用孕早期流产后机械刮宫方法成功构建IUA大鼠模型,该模型大鼠妊娠能力降低、子宫内膜组织腺体数目减少、纤维化程度增加,TGF-β1表达升高。

Objective The intrauterine adhesion(IUA)model was established by mechanical curettage after embryo removal by cesarean section in early-trimester rats,and its function was evaluated.Methods Forty-eight SD female rats with stable estrous cycles aged 8-9 weeks were randomly divided into groups A,B,C,and D,with 12 rats in each group.In the groups A,B,and C,after female mice and male mice were placed together,we screened pregnant rats(recorded as the 0.5th day of pregnancy).On the 5.5th to 6.5th day of pregnancy,the IUA model was established by mechanical curettage after the embryos were removed by cesarean section in the first trimester.The female rats in the group D were raised alone without male rats.We sutured and closed their abdomen without curettage.Rats in the groups A,B,and C were continued to feed for 1,2,and 3 estrous cycles after curettage.Six rats in each group were sacrificed,and uterine tissues were collected.After HE staining,the number of endometrial glands in each group was calculated.The degree of endometrial fibrosis in rats of each group was observed by using Masson staining method,and TGF-β_(1) in the endometrial tissues was detected by immunohistochemistry.The remaining six rats in each group were randomly assigned to male rats and caged,and the pregnant rats were sacrificed on the 14.5th day of gestation,and the number of embryos in the uterus was recorded.Results Compared with group D,rats in groups A,B,and C had fewer endometrial glands,higher scores of endometrial fibrosis,and higher relative expression of TGF-β_(1)(all P<0.05).Compared with groups B and C,the number of endometrial glands was more,the score of fibrosis was lower,and the relative expression of TGF-β_(1) was lower in the group A(all P<0.05).On the 14.5th day of pregnancy,the number of bilateral uterine embryos in the groups A,B,C,and D were 2.08±1.16,0,0,and 6.75±1.14,respectively.Compared with group D,the number of bilateral uterine embryos in the group A was smaller(P<0.05).Conclusions The IUA rat model is successfully established by mechanical curettage after abortion in early-trimester rats.The model rats have decreased pregnancy ability,decreased number of endometrial glands,increased fibrosis,and increased TGF-β_(1) expression.