米非司酮（RU486）对早孕人滋养细胞超微结构的影响

研究米非司酮（ＲＵ４８６）对早孕人滋养细胞超微结构的影响时，发现ＲＵ４８６可使滋养细胞发生核溶解，粗面内质网渠扩张，线粒体缩小和合体细胞片段脱落等形态改变。虽然ＲＵ４８６可在受体水体拮抗孕酮，但在滋养细胞及在脱膜细胞均无凋亡现象发生。说明ＲＵ４８６对上述组织的影响是继发的，其终止早孕的主要机理可能与子宫螺旋动脉减少供血有关。

The Effect of Mifepristone (RU486) on the Ultrastructure of Human Trophoblastic Cells During the Early Pregnancy

Studying the effect of Mifepristone (RU486) on ultrastructure of human trophoblastic cells during the early pregnancy, we found that RU486 caused the trophoblastic cells to dis-play morphological changes such as caryolysis, rough endoplasmic reticulum dilatation, mitochondria shrinkage and syncytial epithelium dissociation etc. Although RU486 is progesterone antagonist in receptor level, no apoptotic cell death was found in the trophoblastic cells. According to referred data, only degeneration or necrosis takes place in the decidua cells under RU486 effect. These findings indicated that the morphological changes both in the trophoblastic cells and decidua cells are resulted from secondary effect of RU486. The mecha-nism of RU486 to terminate the early pregnancy may be connected with the decrease blood supply of the utrine spiral arteries.