Chloride Efflux During the Progesterone-Initiated Human Sperm Acrosome Reaction Is Inhibited by Lavendustin A, a Tyrosine Kinase Inhibitor

J Androl. Jul-Aug 1996;17(4):327-30.


Previous studies showed that progesterone (P) can initiate the mammalian sperm acrosome reaction (AR) in vitro and that a sperm GABAA-like receptor/Cl- channel is involved in an essential Cl- efflux mediated by P during the AR. Here, we show that lavendustin A, a potent, specific inhibitor of tyrosine kinase activity, strongly inhibits the P-initiated human AR and the essential P-mediated Cl- efflux. Lavendustin B, a weak tyrosine kinase inhibitor, had no significant effect. These results suggest that, as part of AR initiation, P mediates tyrosine phosphorylation of the sperm GABAA- like receptor/Cl- channel.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acrosome / drug effects*
  • Acrosome / physiology*
  • Chloride Channels / physiology*
  • Enzyme Inhibitors / pharmacology*
  • Fluorescent Dyes
  • Humans
  • Male
  • Phenols / pharmacology*
  • Progesterone / pharmacology*
  • Protein-Tyrosine Kinases / antagonists & inhibitors


  • Chloride Channels
  • Enzyme Inhibitors
  • Fluorescent Dyes
  • Phenols
  • lavendustin A
  • Progesterone
  • Protein-Tyrosine Kinases