Evidence for a role of cysteinyl leukotrienes in mouse and human sperm function

The in vitro fertilizing capacity of mouse spermatozoa was inhibited by FPL‐55712, a receptor antagonist of the cysteinyl‐containing leukotrienes LTC4, LTD4, and LTE4. Inhibition occurred whether the compound was present in the medium during the capacitation period or during the fertilization period. Additionally, FPL‐55712 inhibited the penetration of human spermatozoa into zona‐free hamster oocytes. Inhibition of fertilization did not appear to be caused by an effect on sperm motility or on the oocyte. These observations suggest that mouse and human spermatozoa require cysteinyl leukotriene activity for both fertilization and oocyte penetration.