title: Effect of norethisterone and its A-ring reduced metabolites on the acrosome reaction in porcine spermatozoa.
abstract: The synthetic progestin, norethisterone (NET), has been reported as a contragestational postcoital agent in humans, rodents and rabbits. The effect and molecular mechanisms of NET and its A-ring reduced metabolites, 5alpha-NET and 3beta5alpha-NET, on the acrosome reaction (AR) are unknown. The aim of this study was to assess the effect of these compounds on an in vitro progesterone-induced AR in porcine spermatozoa. The spermatozoa were obtained from semen ejaculated by proven fertile adult pigs. Seminal plasma removed and incubated under capacitating conditions was performed in TALP-Hepes medium for 4 h. Progesterone (P4) and three different progestins: norethisterone (NET), 5alpha-norethisterone (5alpha-NET) and 3beta5alpha-NET were then added at equimolar doses, and the spermatozoa were incubated for 15 min. Double-staining with PSA-FITC and Hoechst-33258 assessed the AR and sperm viability. Both P4 and NET induced the AR, while 5alpha-NET not only did not induce this process, but was able to block the effect of P4 on the spermatozoa. 3beta5alpha-NET was not able to inhibit P4 action. These results suggest that NET and its A-ring reduced metabolites act in different ways on the progesterone-induced AR in porcine spermatozoa.
authors.affiliation: Instituto Nacional de Perinatología, México City, México.
authors.forename: G
authors.initials: G
authors.lastname: Martinez
authors.forename: H
authors.initials: H
authors.lastname: Zayas
authors.forename: Y
authors.initials: Y
authors.lastname: Ducolomb
authors.forename: G A
authors.initials: GA
authors.lastname: Garcia
authors.forename: M
authors.initials: M
authors.lastname: Betancourt
authors.forename: I
authors.initials: I
authors.lastname: Castro
mesh_terms: D020101:Acrosome Reaction / Q000187:drug effects*; D000818:Animals; D004347:Drug Interactions; D066298:In Vitro Techniques; D008297:Male; D009640:Norethindrone / Q000378:metabolism / Q000494:pharmacology*; D011374:Progesterone / Q000494:pharmacology; D013094:Spermatozoa / Q000187:drug effects* / Q000502:physiology; D013552:Swine
chemical_list: D011374:Progesterone; D009640:Norethindrone