Sth Chan

Vero cells, but not oviductal cells, increase the hatching frequency and total cell count of mouse blastocysts partly by changing energy substrate concentrations in culture medium

AbstractPurpose: To investigate the embryotrophic mechanisms of Vero and oviductal cells coculture. Methods: Mouse embryos were cultured in Chatot, Ziomek, and Bavister medium (CZB), in modified CZB media (MM) with nutrient concentrations adjusted to that found in conditioned media after different periods of Vero cells or oviductal cells culture, in reconstituted medium (RM) containing the purified >100-kDa components of Vero cell conditioned medium that had been reconstituted with CZB medium, and cocultured with Vero cells with an interposing membrane. Results: The blastulation rate was not different among embryos cultured in different Vero-cell–derived MMs. Nine-hour Vero-cell-derived MM significantly increased the total cell number and hatching frequency of the embryos. There was no difference in these parameters with oviductal-cell–derived MMs. The RM of Vero cells did not possess embryotrophic activity. The presence of a porous membrane between Vero cells and embryos did not affect the embryotrophic activity of coculture. Conclusions: Vero cells, but not oviductal cells, improved mouse embryo development partly by modifying the energy substrate concentration in culture medium.

Early pregnancy in human may not be associated with mild thrombocytopenia.

Both human (1) and mouse (2) preimplantation embryos have been found to produce a soluble platelet-activating factor (PAF) in vitro. This embryoderived PAF (EDPAF) showed similar chemical, biochemical, and physiological properties to PAFacether, 1-O-alkyl-2-acetyl-sn-glyceryl-3-phosphocholine (3,4). Early pregnancy-associated thrombocytopenia (EPAT) was observed in the peripheral blood of pregnant female mice. Experimental evidence indicated that this initial maternal response to conception with an increase in platelet activation and a consequent reduction in peripheral platelet count was due to the production of EDPAF from the zygote (5). A bioassay had also been developed to measure the EDPAF (3). In order to eliminate the compensatory release of platelets by the spleen in response to EPAT, splenectomized mouse was used in this assay. In a previous survey of 24 patients undergoing in vitro fertilization/embryo transfer (IVF/ET), pregnancy was always associated with EPAT in the first 3-5 days following embryo transfer, although the reverse might not be true (6). Serum from successfully treated IVF patients could induce thrombocytopenia in splenectomized mouse (7). In the present study, we undertook a more extensive study on the possible occurrence of EPAT in patients receiving various subfertility therapies, namely, IVF/ET, gamete intrafallopian transfer (GIFT), artificial insemination by husband (AIH), and induction of ovulation with human menopausal gonadotropin (hMG).