title: Localization of met-enkephalin on human spermatozoa and evidence for its physiological role.
abstract: Pro-opio-melano-cortino-derived peptides have been identified in rat testicular extracts and in human seminal plasma, but their physiological role is still unknown. We report that met-enkephalin is localized on human spermatozoa, by means of an indirect immunofluorescent technique. Furthermore, we demonstrate that a met-enkephalin analog (D-Ala2-Mephe4-Met-(o)-ol-enkephalin, FK 33-824, Sandoz, Basel, Switzerland: DAMME) inhibits in a dose-dependent manner the acrosome reaction induction. The hypothesis of a physiological role of seminal met-enkephalin on human spermatozoa fertilizing ability is briefly discussed.
mesh_terms: D000177:Acrosome / Q000187:drug effects; D000328:Adult; D005405:D-Ala(2),MePhe(4),Met(0)-ol-enkephalin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004744:Enkephalin, Methionine / Q000032:analysis*; D005455:Fluorescent Antibody Technique; D006801:Humans; D008297:Male; D009270:Naloxone / Q000494:pharmacology; D012661:Semen / Q000032:analysis; D013094:Spermatozoa / Q000032:analysis*
chemical_list: D009270:Naloxone; D004744:Enkephalin, Methionine; D005405:D-Ala(2),MePhe(4),Met(0)-ol-enkephalin