Anandamide Induces Sperm Release from Oviductal Epithelia through Nitric Oxide Pathway in Bovines

OSYCKA-SALUT CLAUDIA; GERVASI, MARIA GRACIA; PEREYRA ELBA; CELLA, MAXIMILIANO; RIBEIRO MARIA LAURA; FRANCHI, ANA MARIA; PEREZ-MARTINEZ, SILVINA

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2012 vol. 7 p. 30671 - 30678

1932-6203

Mammalian spermatozoa are not able to fertilize an egg immediately upon ejaculation. They acquire this ability during theirtransit through the female genital tract in a process known as capacitation. The mammalian oviduct acts as a functionalsperm reservoir providing a suitable environment that allows the maintenance of sperm fertilization competence untilovulation occurs. After ovulation, spermatozoa are gradually released from the oviductal reservoir in the caudal isthmus andascend to the site of fertilization. Capacitating-related changes in sperm plasma membrane seem to be responsible forsperm release from oviductal epithelium. Anandamide is a lipid mediator that participates in the regulation of severalfemale and male reproductive functions. Previously we have demonstrated that anandamide was capable to releasespermatozoa from oviductal epithelia by induction of sperm capacitation in bovines. In the present work we studiedwhether anandamide might exert its effect by activating the nitric oxide (NO) pathway since this molecule has beendescribed as a capacitating agent in spermatozoa from different species. First, we demonstrated that 1 mM NOC-18, a NOdonor, and 10 mM L-Arginine, NO synthase substrate, induced the release of spermatozoa from the oviductal epithelia.Then, we observed that the anandamide effect on sperm oviduct interaction was reversed by the addition of 1 mM L-NAME,a NO synthase inhibitor, or 30 mg/ml Hemoglobin, a NO scavenger. We also demonstrated that the induction of bull spermcapacitation by nanomolar concentrations of R(+)-methanandamide or anandamide was inhibited by adding L-NAME orHemoglobin. To study whether anandamide is able to produce NO, we measured this compound in both sperm andoviductal cells. We observed that anandamide increased the levels of NO in spermatozoa, but not in oviductal cells. Thesefindings suggest that anandamide regulates the sperm release from oviductal epithelia probably by activating the NOpathway during sperm capacitation.