title: Effect of genistein on acrosome reaction and zona pellucida binding independent of protein tyrosine kinase inhibition in bull.
abstract: OBJECTIVE
  To investigate if the phytoestrogen, genistein, affects essential functions of cryopreserved bovine spermatozoa.
  
  
  METHODS
  The effect of genistein upon motility was assessed by computer-assisted motion analysis. Hemizona assay was performed to detect the ability of spermatozoa binding to the zona pellucida. The inducibility of the acrosome reaction using progesterone and ZP3-6 peptide was analysed by fluorescein-conjugated Pisum sativum agglutinin (FITC-PSA)/Hoechst 33258 double staining. Capacitation after incubation with genistein was assessed by the chlortetracycline (CTC) assay. Immunoblots showed the pattern of protein tyrosine phosphorylation of cryopreserved bovine spermatozoa.
  
  
  RESULTS
  Immunodetection of tyrosine-phosphorylated proteins showed that genistein did not affect tyrosine phosphorylation in cryopreserved bovine spermatozoa. However, genistein significantly reduced the progesterone- and ZP3-6 peptide-mediated induction of the acrosome reaction and led to a dose-dependent inhibition of sperm-zona pellucida binding; while sperm motility and capacitation were not affected by this phytoestrogen, as indicated by computer-assisted sperm motion analysis and the CTC assay, respectively.
  
  
  CONCLUSIONS
  Our results suggest that in cryopreserved bovine spermatozoa, genistein affects a protein tyrosine phosphorylation-independent signal transduction pathway that is involved in sperm capacitation, the acrosome reaction and sperm-zona pellucida binding.
authors: Center of Dermatology and Andrology, Justus Liebig University Giessen, Giessen, Germany. vivianamenzel@gmx.de
authors: Viviana A
authors: VA
authors: Menzel
authors: Elvira
authors: E
authors: Hinsch
authors: Wolfgang
authors: W
authors: Hägele
authors: Klaus-Dieter
authors: KD
authors: Hinsch
mesh_terms: D020101:Acrosome Reaction / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D002417:Cattle; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019833:Genistein / Q000494:pharmacology*; D008297:Male; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D013075:Sperm Capacitation / Q000187:drug effects / Q000502:physiology*; D015044:Zona Pellucida / Q000187:drug effects / Q000502:physiology*
chemical_list: D004791:Enzyme Inhibitors; D019833:Genistein; D011505:Protein-Tyrosine Kinases