Chloride efflux during the progesterone-initiated human sperm acrosome reaction is inhibited by lavendustin A, a tyrosine kinase inhibitor.
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.
Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis 95616-8643, USA.
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Meizel
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Turner
D000177:Acrosome / Q000187:drug effects* / Q000502:physiology*; D018118:Chloride Channels / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005456:Fluorescent Dyes; D006801:Humans; D008297:Male; D010636:Phenols / Q000494:pharmacology*; D011374:Progesterone / Q000494:pharmacology*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors
D018118:Chloride Channels; D004791:Enzyme Inhibitors; D005456:Fluorescent Dyes; D010636:Phenols; C062898:lavendustin A; D011374:Progesterone; D011505:Protein-Tyrosine Kinases