Effect of mifepristone on human sperm function in vitro

Abstract

Objective: Mifepristone, as a type of well-accepted emergency contraceptive drugs, is an optional progesterone receptor modulator and widely used clinically. However, the effect of mifepristone on sperms is poorly studied. This research is intended to investigate the biological effect of mifepristone on human sperm function in vitro.

Methods: Spermatozoa were incubated in the culture medium containing 0.04 μM, 0.4 μM, 4 μM and 40 μM of mifepristone for one hour after capacitation. It was required to measure sperm motility, viability, DNA integrity, acrosomal reaction, sperm hyperactivation, and the concentration of free calcium ions in spermatozoa.

Results: After treating sperms with different concentrations of mifepristone in vitro, sperm viability, motility, morphology and DNA integrity were measured. The differences between the control group and the experimental group were of no statistical significance (p > .05). When the concentration of mifepristone was higher than 0.4 μM, the proportion of sperm hyperactivation was significantly reduced (p < .01). According to further examination on the rate of acrosomal reaction (AR rate) and the concentration of free calcium ions in sperms, it was found that acrosomal reaction was significantly inhibited with the concentration of free calcium ions in sperms decreased when the concentration of mifepristone was higher than 0.4 μM.

Conclusions: The in-vitro spermicidal mechanism of mifepristone is realized by inhibiting acrosomal reaction, hyperactivation and decreasing the concentration of free calcium ions.