米非司酮混悬液灌胃制备小鼠不完全型胚胎着床障碍模型的适宜剂量选择OACSTPCD

Objective To select the appropriate dosage of mifepristone suspension to prepare the mouse models of incomplete embryo implantation dysfunction(EID).Methods Thirty-two Kunming female mice were randomly divided into four groups:the control group,the low-dose,medium-dose,and high-dose groups,with 8 mice in each group.Mice in the low-dose group,medium-dose group,and high-dose group were given 0.12,0.14,and 0.16 mL of mifepristone suspension(1 mg/mL)by gavage on the 4th day of pregnancy to prepare the incomplete EID models.Mice in the control group were given an appropriate amount of normal saline,and the mice were euthanized on the 8th day of pregnancy.Se-rum estradiol(E2)and progesterone(P)were detected using ELISA.Uterine morphology was observed by naked eye,pregnancy rate and embryo implantation number were calculated,and endometrial tissue was observed by HE staining.Progesterone receptor(PR)in the endometrial tissues was detected by immunohistochemistry.Results No significant difference was found in the serum E2 or P levels between groups(all P>0.05).The control group had all pregnancies,with evenly enlarged uterus on both sides,abundant uterine blood supply,tightly distributed embryo implantation points without bleeding points,and good embryo development.The low-dose group had all pregnancies,and there were no abnor-malities in the appearance and embryonic development of the bilateral uterus;the uterine blood supply was worse than that of the control group.The medium-dose group had all pregnancies,with irregular distribution of embryo implantation points on both sides of the uterus;some embryos had blood accumulation at the implantation site,and the embryo volume was small;the uterus at the non-implantation site was thinner,pale in color,and had poor blood supply.The high-dose group only had one pregnancy,with regular bilateral uterine morphology,pale color,poor blood supply,and poor bilateral uter-ine elasticity.The pregnancy rate of the high-dose group was lower than those of the other three groups(all P<0.05).Com-pared with the low-dose group and control group,the number of embryo implantation in the medium-dose group and high-dose group was smaller(P<0.05);compared with the medium-dose group,the high-dose group had smaller embryo im-plantation number(P<0.05).The control group had extensive decidualization reaction in the endometrial stroma,with a large number of glands and a large glandular cavity area;the glandular cavity contained secretions with small vessel prolif-eration.The low-dose group showed significant endometrial stromal decidua and a large number of glands;the endometri-um of the medium-dose group showed decidualization changes,with denser stroma,fewer and smaller glands,and less ob-vious vascular dilation;the high-dose group had incomplete decidualization in the endometrial stromal area,with small and few glands,insufficient secretion,dense endometrial stroma,still showing proliferative phase like changes,and signif-icantly delayed development.Compared with the control group and the low-dose group,the PR AOD of the medium-dose group and the high-dose group decreased(both P<0.05);compared with the medium-dose group,the high-dose group showed a decrease in PR AOD(P<0.05).Conclusion The preparation of incomplete EID mouse models using mifepris-tone is stable and reliable,with an appropriate dose of 0.16 mL/mouse(1 mg/mL).