title: Stimulation of the nitric oxide/cyclic guanosine monophosphate signaling pathway elicits human sperm chemotaxis in vitro.
abstract: OBJECTIVE
  To investigate whether nitric oxide (NO) may attract human spermatozoa via activation of the soluble guanylate cyclase (sGC)/cyclic guanosine monophosphate (cGMP) pathway.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Academic research institution.
  
  
  METHODS
  Seven normozoospermic patients belonging to couples presenting for infertility evaluation.
  
  
  METHODS
  Sperm samples were processed by the swim-up technique.
  
  
  METHODS
  Sperm chemotaxis detected by a choice device (specially designed three-well plexiglass chamber), intracellular level of cGMP (by radioimmunoassay), and sperm motility parameters (by computer-assisted sperm analysis).
  
  
  RESULTS
  After a 20-minute incubation, the NO donor S-nitrosoglutathione (GSNO) increased the synthesis of cGMP and exerted a significant chemoattraction on human spermatozoa. The GSNO-induced migration of sperm was inhibited by PTIO (a NO scavenger), ODQ (an sGC inhibitor), and Rp-8-Br-cGMPS (an inhibitor of cGMP-dependent protein kinases). The cell-permeating cGMP analog 8-Br-cGMP acted as a potent chemoattractant per se: this effect was inhibited by Rp-8-Br-cGMPS.
  
  
  CONCLUSIONS
  These data suggest that NO may exert a chemoattractant effect on human spermatozoa and that the signal transduction involves the activation of sGC, the synthesis of cGMP, and the activation of cGMP-dependent protein kinases.
authors.affiliation: Department of Genetics, Biology and Biochemistry, University of Torino, 10126 Torino, Italy.
authors.forename: Erica
authors.initials: E
authors.lastname: Miraglia
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Rullo
authors.forename: Amalia
authors.initials: A
authors.lastname: Bosia
authors.forename: Marco
authors.initials: M
authors.lastname: Massobrio
authors.forename: Alberto
authors.initials: A
authors.lastname: Revelli
authors.forename: Dario
authors.initials: D
authors.lastname: Ghigo
mesh_terms: D002633:Chemotaxis / Q000187:drug effects / Q000502:physiology*; D006152:Cyclic GMP / Q000502:physiology*; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000819:agonists / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D011446:Prospective Studies; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013081:Sperm Motility / Q000187:drug effects / Q000502:physiology; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology*
chemical_list: D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D006152:Cyclic GMP