Inhibition of phospholipase C reduces the capacitation of cryopreserved ovine sperm

This study aimed to evaluate the effect of phospholipase C (PLC) on the capacitation of cryopreserved ovine semen. Sixteen semen samples were cryopreserved with diluent added by 0, 10, or 20 mu M of U73122, a PLC inhibitor. The sperm kinetics of the thawed samples were evaluated using the Computer-assisted Sperm Anal-ysis system, and the integrity of the plasma and mitochondrial membranes was evaluated using fluorescent probes. Additionally, sperm capacitation and the acrosome reaction with chlortetracycline hydrochloride were evaluated before and after capacitation induction. The results were analysed using analysis of variance and Tukey's test with a 95% probability. Concentrations of 10 or 20 mu M of U73122 did not affect the kinetics or number of sperm with intact plasma and mitochondrial membranes. However, after thawing, 10 and 20 mu M of the inhibitor reduced the percentage of capacitated and acrosome-reacted sperm. After induction of capacitation, there was a reduction in the number of non-capacitated sperm in all treatment groups, suggesting a reversible effect of U73122. In conclusion, U73122 at concentrations of 10 or 20 mu M prevents premature capacitation and acrosome reaction induced by the freezing procedure, without affecting the kinetics and integrity of the sperm membranes.

Automated summary

This study evaluated the effect of phospholipase C (PLC) on the capacitation of cryopreserved ovine semen. The results showed that the inhibitor U73122 can prevent premature capacitation and acrosome reaction induced by the freezing procedure, without affecting the kinetics and integrity of the sperm membranes.