Wakuda K, Takakura K, Nakanishi K, Kita N, Shi H, Hirose M, Noda Y
Department of Obstetrics and Gynecology, Shiga University of Medical Science, Japan.
J Reprod Fertil. 1999 Mar;115(2):315-24. doi: 10.1530/jrf.0.1150315.
The effect of intraoviductal embryos on endometrial receptivity was studied by intraendometrial and intrauterine embryo transfer. Five-week-old female ICR mice were mated after superovulation; a vaginal plug confirmed day 1 of pregnancy. On day 4 (90 h after hCG injection), blastocysts were collected and transferred to pseudopregnant female mice and to recipient mice in which the uterotubal junction had been ligated bilaterally on day 1 of pregnancy. Three embryos per uterine horn, a total of six embryos per recipient mouse at days 1-6, were transferred to the endometrium or uterine cavity and implantation and pregnancy rates were calculated. The implantation rate for intraendometrial embryo transfer to recipients of days 3, 5 and 6 was significantly higher for uterotubal junction-ligated mice (72.2, 20.8 and 9.7%, respectively) than for pseudopregnant mice (55.0, 8.3 and 0.0%, respectively). The implantation rate for intrauterine embryo transfer to recipients at days 2, 5 and 6 was significantly higher for uterotubal junction-ligated mice (11.1, 25.0 and 8.3%, respectively) than for pseudopregnant mice (0.0, 3.3 and 0.0%, respectively). Uterotubal junction-ligated mice achieved implantation and bore neonates by intrauterine embryo transfer on days 2 and 6, whereas no implantation was achieved in pseudopregnant mice. The difference in implantation rate could not be explained by a difference in progesterone concentration between the groups. The distribution of proliferating cells in the endometrium was also studied immunohistochemically by use of anti-proliferating cell nuclear antigen (PCNA) antibody in the recipient mice. PCNA-positive cells were more abundant in uterotubal junction-ligated mice and demonstrated a marked extension from the epithelium to the stroma over time, in contrast to those in pseudopregnant mice. These findings indicate that an intraoviductal embryo exerts a biological effect by sending a signal to the endometrial epithelium and stroma, thus facilitating endometrial receptivity to the embryo and improving the rate of implantation.
通过子宫内膜内和子宫内胚胎移植研究输卵管内胚胎对子宫内膜容受性的影响。对5周龄雌性ICR小鼠进行超排卵后交配；阴道栓确认妊娠第1天。在第4天（注射hCG后90小时），收集囊胚并将其移植到假孕雌性小鼠以及在妊娠第1天双侧结扎子宫输卵管连接处的受体小鼠体内。在第1 - 6天，将每个子宫角植入3个胚胎，每个受体小鼠共植入6个胚胎，分别移植到子宫内膜或子宫腔内，并计算着床率和妊娠率。对于子宫输卵管连接处结扎的小鼠，在第3、5和6天进行子宫内膜内胚胎移植的着床率（分别为72.2%、20.8%和9.7%）显著高于假孕小鼠（分别为55.0%、8.3%和0.0%）。对于子宫输卵管连接处结扎的小鼠，在第2、5和6天进行子宫内胚胎移植的着床率（分别为11.1%、25.0%和8.3%）显著高于假孕小鼠（分别为0.0%、3.3%和0.0%）。子宫输卵管连接处结扎的小鼠在第2天和第6天通过子宫内胚胎移植实现着床并产下幼崽，而假孕小鼠未实现着床。着床率的差异不能用两组之间孕酮浓度的差异来解释。还通过使用抗增殖细胞核抗原（PCNA）抗体对受体小鼠子宫内膜中增殖细胞的分布进行了免疫组织化学研究。与假孕小鼠相比，子宫输卵管连接处结扎的小鼠中PCNA阳性细胞更为丰富，并且随着时间的推移从上皮细胞向基质细胞显著扩展。这些发现表明，输卵管内胚胎通过向子宫内膜上皮和基质发送信号发挥生物学作用，从而促进子宫内膜对胚胎的容受性并提高着床率。
