title: Progesterone effect mediated by the voltage-dependent calcium channel and protein kinase C on noncapacitated cryopreserved bovine spermatozoa.
abstract: An increase in intracellular calcium is essential to trigger capacitation and the acrosome reaction. The aim of this study was to determine the progesterone effect mediated by the voltage-dependent calcium channel and protein kinase C on heparin-capacitated and noncapacitated spermatozoa. Protein kinase C was activated by 1-oleoyl-2-acetyl glycerol, a membrane-permeant diacyl-glycerol, and inhibited by GF-109203X. The percentage of true acrosome reaction was evaluated using differential-interferential optical contrast microscopy and trypan blue stain. The calcium concentration was evaluated by FURA-2AM and methoxyverapamil was used as a voltage-dependent calcium channel inhibitor. A rapid calcium increase and acrosome reaction were induced by progesterone in capacitated and noncapacitated spermatozoa, a higher intracellular calcium increase being observed in capacitated than in noncapacitated samples (P < 0.05). The calcium increase and acrosome reaction were blocked significantly by GF-109203X in noncapacitated and capacitated spermatozoa by the addition of progesterone and/or 1-oleoyl-2-acetylglycerol. Methoxyverapamil blocked calcium influx in samples treated with progesterone and heparin/progesterone, but not in those treated with 1-oleoyl-2-acetyl glycerol. Progesterone induces the acrosome reaction in noncapacitated cryopreserved bovine spermatozoa through intracellular mechanisms dependent on protein kinase C and the voltage-dependent calcium channel.
authors.affiliation: Area of Biochemistry, School of Veterinary Sciences, University of Buenos Aires, Buenos Aires, Argentina.
authors.forename: M
authors.initials: M
authors.lastname: Córdoba
authors.forename: M T
authors.initials: MT
authors.lastname: Beconi
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000502:physiology*; D002417:Cattle; D015925:Cryopreservation; D004075:Diglycerides / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D005711:Gallopamil / Q000494:pharmacology; D006493:Heparin / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D008297:Male; D008301:Maleimides / Q000494:pharmacology; D011374:Progesterone / Q000494:pharmacology*; D011493:Protein Kinase C / Q000378:metabolism*; D012662:Semen Preservation; D013075:Sperm Capacitation; D013094:Spermatozoa / Q000187:drug effects* / Q000502:physiology
chemical_list: D015220:Calcium Channels; D004075:Diglycerides; D007211:Indoles; D008301:Maleimides; D005711:Gallopamil; D011374:Progesterone; C038237:1-oleoyl-2-acetylglycerol; D006493:Heparin; D011493:Protein Kinase C; C070515:bisindolylmaleimide I; D002118:Calcium