title: Participation of membrane adenylyl cyclase in heparin-induced capacitation in cryopreserved bovine spermatozoa.
abstract: The aim of this work was to study the participation of membrane adenylyl cyclase in heparin-induced capacitation in cryopreserved bovine spermatozoa. Sperm suspensions were incubated in Tyrode's albumin lactate pyruvate medium in the presence of heparin (10 IU ml(-1) ) or forskolin (1-75 μm), a well-known membrane adenylyl cyclase activator. The participation of membrane adenylyl cyclase was confirmed using a specific inhibitor, 2',5'-dideoxyadenosine (6-25 μm). Spermatozoa capacitated with forskolin (25 μm) were incubated with bovine follicular fluid to evaluate their ability to undergo acrosome reaction. Capacitation percentages were determined by the fluorescence technique with chlortetracycline, and true acrosome reaction was determined by trypan blue and differential interferential contrast. The forskolin concentrations employed had no effect on progressive motility or sperm viability. Capacitation values induced by 25-μm forskolin treatment (27.80 ± 2.59%) were significantly higher respect to the control (4.80 ± 1.30%). The inhibitor 2',5'-dideoxyadenosine prevented forskolin-induced capacitation and significantly diminished capacitation induced by heparin. Follicular fluid induced physiological acrosome reaction in spermatozoa previously capacitated with 25-μm forskolin (P < 0.05). Forskolin acts as a capacitation inducer and involves the participation of membrane adenylyl cyclase as part of the intracellular mechanisms that lead to capacitation in cryopreserved bovine spermatozoa.
authors.affiliation: Biological Chemistry, INITRA, School of Veterinary Science, University of Buenos Aires (UBA), Buenos Aires, Argentina.
authors.forename: M C
authors.initials: MC
authors.lastname: Ricart
authors.forename: E
authors.initials: E
authors.lastname: Breininger
authors.forename: P C
authors.initials: PC
authors.lastname: Rodriguez
authors.forename: M T
authors.initials: MT
authors.lastname: Beconi
mesh_terms: D020101:Acrosome Reaction / Q000187:drug effects* / Q000502:physiology; D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000502:physiology*; D000818:Animals; D000963:Antimetabolites / Q000494:pharmacology; D002417:Cattle; D002470:Cell Survival; D005576:Colforsin / Q000494:pharmacology; D015925:Cryopreservation; D016048:Dideoxyadenosine / Q000494:pharmacology; D005343:Fibrinolytic Agents / Q000494:pharmacology*; D006493:Heparin / Q000494:pharmacology*; D008297:Male; D012662:Semen Preservation; D013075:Sperm Capacitation / Q000187:drug effects* / Q000502:physiology; D013081:Sperm Motility / Q000187:drug effects / Q000502:physiology; D013094:Spermatozoa / Q000187:drug effects* / Q000502:physiology
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D000963:Antimetabolites; D005343:Fibrinolytic Agents; D005576:Colforsin; D016048:Dideoxyadenosine; D006493:Heparin; D000262:Adenylyl Cyclases
keywords: Adenylyl cyclase; bovine; membrane adenylyl cyclase; sperm