Development and characterization of an endometrial tissue culture model for study of early implantation events.

To improve and characterize an endometrial tissue culture model.Experimental study of the characteristics of mouse endometrial tissue cultured on amniotic membrane matrix.University research laboratory.Sexually mature female ICR mice.Histologic examination of the cultured endometrial tissues. The attachment rates of the cultured tissues to implantation blastocysts under various conditions were determined.Morphometric analysis of the cultured tissues. Blastocyst attachment rate and expression of decidualization markers cylcooxygenase-2, connexin 43, and peroxisome proliferator-activated receptor δ.Endometrial tissues could be grown on amniotic membrane matrix for 3 days with morphometric parameters similar to those in the in vivo pseudopregnant control. The cultured tissues responded to the surrounding steroid environment. Morphometric assessment indicated that medium containing 63.5 nmol/L P and 0.9 nmol/L E(2) provided the best support. The condition allowed attachment of approximately 60% of the cocultured blastocysts. A small percentage of the attached blastocyst started to penetrate the luminal epithelium within 28 hours. The attachment rate was significantly reduced with prior treatment of the cultured endometrium with anti-leukemia inhibitory factor antibody. The attached blastocyst induced decidualization around the attachment site.The model is useful for the study on implantation in the mouse.