227. An inhibitor of leukemia inhibitory factor signalling blocks embryo implantation in the mouse

Abstract

Embryo implantation is a critical step in the establishment of pregnancy. Endometrial leukemia inhibitory factor (LIF) is essential for embryo implantation in the mouse (1). Uterine LIF is expressed in the luminal epithelium on Day 3 of pregnancy (D3) (D0 = day of plug detection) and signals via activation of signal transducer and activator of transcription (Stat) 3 (2). We examined the effect of a novel LIF signalling inhibitor on the phosphorylation (p) of Stat3 during early pregnancy and on embryo implantation in the mouse. We injected LIF inhibitor into one uterine horn and PBS into the other uterine horn of the mouse at D3 and examined the effect on pStat3 immunostaining in th..