Induction Of Acrosome Reaction Of Wapiti (Cervus Elaphus) Sperm And The Effects On Ions Transport Using A23187 & Valinomycin

Sperm acrosome reaction (AR) is prerequisite to mammalian fertilization. Studies on AR and its mechanism is important to mammalian heredity, breeding and reproduction in practice as well as in theories. In this paper, induction of AR of wapiti (Cervus elaphus) sperm using calcium ionophore A23187 (A23187) and potassium ionophore valinomycin (Val) and their effects on ions transport were studied. Wapiti sperm was capacitated by the method of swiming-up and AR was induced by A23187 and Val. The AR rate as a main criterion, and the mobility or viability as auxiliary criterion, were used to evaluate the effects of the two inducing factors on sperm AR. The pre- and post-AR concentrations of Ca²⁺ , Mg²⁺ , K⁺, Na⁺, total P in the culture medium were detected by inductive coupled plasma (ICP) , and Cl^- change was measured by ion chromatography, in order to study the effects of A23187 and Val on pre- and post-AR ion transport. The main results of this research are shown as follow:1 When the concentration of DMSO did not exceed 0.5%, it had no effects on viability of wapiti sperm in 2h, whereas the mobility decreased when the concentration exceeded 0.5%.2 AR rates of capacitated wapiti sperm were increased with treatments of 0.01μmol/L-100μmol/L A23187. The most suitable concentration and treatment time for A23187 was 0.1μmol/L for 5 min, which resulted into an AR rate of 74.00±2.62%3 AR rates of capacitated wapiti sperm were increased with 0.01μmol/L-50μmol/L Val. The treatment with Val at 0.5μmol/L for 15 min resulted into the best AR rate of 74.48±0.90%, but it was not significant differences (P>0.05)4 As to combination treatment with A23187 and Val inducing the AR of capacitated wapiti sperm, the best combinations were 0.5μmol/L A23187+10μmol/L Val or 5μmol/L A23187+10μmol/L Val.5 There were no significant effects (P>0.05) on the AR rates of uncapacitated wapiti sperm by alone A23187, Val, or combination of A23187 and Val;there were also no significant effects (P>0.05) on wapiti sperm capacitation.6 The concentration changes of Ca²⁺ , Mg²⁺ , K⁺, Na⁺, total P and Cl^- demonstrated the regulation of A23187 or Val on ions transport during the 10 min after they induced AR of wapiti sperm.