IIBYT   23944
INSTITUTO DE INVESTIGACIONES BIOLOGICAS Y TECNOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
HUMAN SPERM CHEMOREPULSION, A NOVEL REGULATION FOR FERTILIZATION?
Autor/es:
GUIDOBALDI, HA; CUBILLA, MC; MORENO, A; MOLINO, MV; BAHAMONDES, L; GIOJALAS, LC
Lugar:
Rosario
Reunión:
Congreso; L Reunión de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Celular; 2014
Institución organizadora:
Sociedad Argentina de Investigaciones en Bioquímica y Biología Celular
Resumen:
Progesterone (P) is secreted by the cumulus cells that surround the oocyte and diffuses generating a concentration gradient along the cumulus and beyond. Under in vitro conditions, sperm can be attracted by a gradient of picomolar dosses of P, mechanism that has been proposed to attract and retain spermatozoa at the fertilization site. Ulipistral acetate (UPA) is a selective progesterone receptor modulator mostly used as an emergency contraceptive which mainly acts as an antagonist of the P receptor. The aim was to evaluate if UPA may regulate human sperm chemotaxis toward P. Sperm chemotaxis was determined by a videomicroscopy-image analysis system and by the Sperm Selection Assay. Spermatozoa were previously incubated with nM doses of UPA (range of concentration determined in women serum after taking a UPA pill) and then exposed to the chemotaxis assay. As expected, UPA significantly inhibited sperm chemotaxis toward P. Surprisingly, UPA also stimulated sperm chemorepulsion from the P attracting source. Sperm repulsive behavior was observed only in the subpopulation of capacitated spermatozoa (those ready to fertilize the oocyte). This is the first observation of sperm chemorepulsion which may have both biological and medical implications, preventing either polyspermy under natural conditions or fertilization under pharmacological treatment with UPA.