LOCALIZACIÓN DE SITIOS DE UNIÓN A HEPARINA EN LA MEMBRANA DEL ESPERMATOZOIDE PORCINO

DORA DAPINO; FERNANDO CANE; PATRICIA ESTELA MARINI; MARCELO O CABADA

Rosario

Congreso; VIII Congreso y XXVI Reunión Anual de la Sociedad de Biología de Rosario; 2006

SBR

Sperm capacitation may be promoted in vitro by the incubation in media that mimic the oviductal fluids. Although a universal medium does not exist, the presence of Ca2+, HCO3- and BSA (bovine seroalbumin) seems to be essential. Previously, we observed an increase in the capacitation values of sperm incubated during 120 min and at 39 ºC, with 10 µg/ml of heparin. To determine the possible interaction between heparin and the mentioned components (Ca2+, HCO3- and BSA), sperm samples from 6 fertile boars were incubated in capacitating media: TALP (CM), non capacitaiting media: (NC) TALP-BSA-Ca2+-HCO3- and combinations: NC+Ca2+, NC+HCO3- and NC+Ca2++HCO3-, in the presence or absence of heparin. Capacitation was assessed by fluorescent chlortetracycline staining (CTC). Statistics: ANOVA. The rate of capacitation between NC,  NC + Ca2+ and NC+ HCO3-  did not differ significantly regardless of the presence of heparin (p>0.05). Sperm capacitation in CM and NC + Ca2+ +  HCO3- showed significant differences with the other media tested (p<0.01). Also, the presence of heparin in these media augments the capacitation (p< 0,05). Conclusions: heparin enhances the in vitro capacitation of pig spermatozoa in the presence of Ca2+ and HCO3-. The absence of BSA did not affect the capacitation, supporting other reports which suggest it is not essential for sperm capacitation in pigs. Cyclic variations in the number of heparin - like glicosaminoglycans in the pig oviduct have been demostrated, suggesting the possibility of an important role of these compounds in fertilization.