Study of the cholesterol transportation mechanism in embryo

小鼠着床前胚胎细胞大小的变化及低密度脂蛋白对胚胎发育的影响。以细胞直径计算的胚胎总细胞体积（TV）在第一次细胞分裂期间下降了29.1%，但总细胞表面积（TA）没有变化。2 ~ 8个细胞期TV不变，但TA每分裂一次增加24 ~ 26%。培养基中的低密度脂蛋白（LDL）不能提高1细胞期培养的胚胎的囊胚率，但能显著增加囊胚早期培养后的滋养细胞外植体面积。而在着床前胚胎发生期间细胞表面积增加，低密度脂蛋白的促进发育作用仅在囊胚期后才观察到。采用免疫组织化学方法测定着床前（妊娠第1 ~ 14天）小鼠子宫内f4 /80阳性巨噬细胞和bm8阳性巨噬细胞的浓度和分布。子宫内膜内，第0-1天可见弥漫性巨噬细胞，第2、3天管腔侧巨噬细胞数量增加。植入开始时（第3-7天），在植入部位周围形成的蜕膜外可见大量巨噬细胞，而蜕膜内未见巨噬细胞。在未去个别化的子宫内膜，在第0-1天可见弥漫性巨噬细胞。此外，本研究表明，在怀孕期间，巨噬细胞不存在于蜕膜形成的早期阶段，但随着蜕膜的增殖，它们从子宫内膜的深层迁移。

Changes in cell size of preimplantation mouse embryos and the influences of low density lipoprotein on the development of embryos. The total cell volume (TV) in an embryo, calculated by the diameters of cells, decreased of 29.1% but the total cell surface area (TA) did not change during the first cell division. During 2 to 8 cell stage TV was constant but TA increased of 24-26% after each division. Low density lipoprotein (LDL) in the culture media did not improve the blastocyst rates of embryos cultured from 1 cell stage, but significantly increased the area of trophoblast outgrowth cultured after the early blastocyst stage. However the cell surface area incresae during preimplantation embryogenesis, the development improving effect of LDL were observed only after the blastocyst stage.The concentration and distribution of F4/80-positive macrophages and BM8-positive macro-phages in the uterus of mice during the preimplantation period (between day 1 and 14 of pregnancy) were assessed immunohistochemically. In the endometrium, macrophages were found diffusely on day 0-1 and the number of these cells increased on the lumen side on day 2 and 3.Upon initiation of implantation (day 3-7), significant numbers of macrophages were found on the outside of the decidua formed around the implantation site, but macrophages were not found within the decidua. In the endo-metrium without decidualization, macrophages were found diffusely on day 0-1.Furthermore, this study demonstrates that, during pregnancy, macrophages are not present within the early stage of decidua-lization, but they migrate from a deep layer of the endometrium following the proliferation of the decidua.