Increased capacitation of buffalo sperm by heparin as confirmed by electron microscopy and in vitro fertilization

Capacitation of buffalo sperm was evaluated by induced acrosome reaction (AR) upon the exposure of 10 mM Ca2+. Culture of sperm for 8 hr in BO medium supplemented with 10 micrograms/ml heparin significantly (P < 0.01) increased the percentage of AR and confirmed by transmission electron microscopy. Vesiculization of outer acrosomal membrane and plasma membrane was observed significantly higher (P < 0.01) following 8 hr of sperm culture with heparin. Culture of sperm with heparin also increased rate of fertilization of in vitro matured oocytes and their subsequent development up to morula/blastocyst stage (P < 0.01). The study demonstrates that capacitation of buffalo sperm by heparin required at least 8 hr exposure of sperm to heparin for maximum acrosome reaction.