Recombinant human leukemia inhibitory factor enhances the development of preimplantation mouse embryo in vitro

Objective: To assess the effect of recombinant human leukemia inhibitory fa ctor (rhLIF) on mouse embryos in vitro. Design: Controlled prospective study. Setting: Academic research environment. Animal(s): Female CB6F1 mice between 6 and 8 weeks old, Intervention(s): Mice were divided randomly into three groups, which includ ed a control group in an in vivo study (group I) and two groups in an in vi tro study (groups II and mi. Mice were killed at 116-120 hours (group I) an d 34-48 hours (groups II and III) after hCG injection. Two-cell embryos (gr oups II and III) and blastocysts (group I) were obtained. Embryos in group II were cocultured with human tubal fluid (HTF) + 0.5% human serum albumin and in group III with HTF + rhLIF (1,000 U/mL) under paraffin oil. Main Outcome Measure(s): The embryonic numbers in different stages were rec orded and compared. Result(s): Similar early embryo development to the four- to eight-cell and morula stages was noted between groups II and III (87.3% versus 91.0% and 7 4.6% versus 87.1%, respectively). However, further embryo development to th e blastocyst, expanded blastocyst, and hatching blastocyst in group II(48.1 %, 31.7%, and 18.5%. respectively) was lower than that in group III (83.6%, 53.7% and 37.8%). Conclusion(s): RhLIF does not provide obvious stimulation in the early mous e embryo. However, rhLIF has positive effects on preimplantation blastocyst growth, differentiation, and hatching. (C) 1999 by American Society for Re productive Medicine.