RESUMEN
OBJECTIVE: To determine the effect of leukemia inhibitory factor (LIF) on the quality of in vitro produced mouse blastocyst and the efficiency of embryonic stem (ES) cell derivation. DESIGN: Experimental study SETTING: Reproductive Medicine Unit, Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University MATERIAL AND METHOD: In vivo fertilized zygotes were collected and subjected to in vitro culture in potassium simplex optimized medium (KSOM) containing 1,000 unit/ml LIF. The developmental ability of the zygote to blastocyst-stage and the cell numbers in blastocysts were evaluated Expanded blastocysts developed in different culture media were subsequently subjected to ES cell derivation. MAIN OUTCOME MEASURE (s): The influence of LIF on the quality of and the total cell numbers of blastocyst developed in vitro. RESULTS: Supplementation of LIF in KSOM increased the rate of hatching blastocysts (63.8% vs. 53.7%; p < 0.05) and total cell numbers (91.4 +/- 15.0 vs. 85.1 +/- 7.7; p < 0.05) compared to KSOM alone. ES cells were obtained 66.7% from blastocysts developed in KSOM-LIF versus 41.7% in KSOM (p > 0.05). Established ES cell lines showed typical colony and characteristics of pluripotent murine ES cells. CONCLUSION: LIF improved the quality of in vitro produced blastocysts but not enhanced ES cell derivation.