LAUSR

Platelet‐activating factor (PAF) affects capacitation, acrosome reaction and fertilisation potential of spermatozoa. This study investigated the underlying mechanism(s) through which PAF regulated sperm function. Our data demonstrated that PAF dose‐dependently induced, whilst lyso‐PAF (PAF precursor) showed no effect on acrosome reaction of capacitated human spermatozoa. Treatment with PAF for 90 min enhanced tyrosine phosphorylation and expression of extracellular signal‐regulated protein kinases (ERK) 1 and 2 in human spermatozoa. Moreover, pre‐treatment with the ERK inhibitor U0126 significantly and dose‐dependently suppressed PAF‐induced acrosome reaction. Therefore, PAF may be actively involved in the modulation of sperm acrosome reaction by interacting with ERK. The role of PAF in fertilisation warrants further investigation.