Effect of leukaemia inhibitory factor on long-term sperm motility and survival

Leukaemia inhibitory factor (LIF) is expressed at high constitutive levels in the human Fallopian tubal epithelium. In this study, the effect of human recombinant LIF on sperm motility and survival in vitro was investigated. Human spermatozoa were incubated in sperm washing medium that contained various concentrations of LIF at 37 degrees C and under 5% of CO(2) in air for up to 48 h. Sperm motion characteristics were measured using a sperm motility analyser. Sperm survival was determined by the hypo-osmotic swelling test. The effect of LIF on sperm motility was concentration-dependent and maximal effect was observed at a concentration of 5 ng/ml. Sperm motility was significantly higher after 24 h exposure to LIF compared with control (P < 0.001). Sperm survival was also prolonged in a concentration-dependent manner. LIF significantly enhanced sperm survival at higher concentrations (10 ng/ml) and the result was significant after 48 h exposure (P < 0.05). LIF increased long-term sperm motility and survival in vitro.