Role of Hydrogen Peroxide in Sperm Capacitation and Acrosome Reaction

摘要: The generation of reactive oxygen species (ROS) has been implicated in the regulation sperm capacitation and acrosome reaction; however, mechanisms underlying this remain unclear. To examine cellular processes involved, we studied effect different concentrations hydrogen peroxide (H(2)O(2)) on protein tyrosine phosphorylation under various conditions. Treatment spermatozoa with H(2)O(2) medium without heparin caused a time- dose-dependent increase at least six proteins which maximal was seen after 2 h incubation 50 microM H(2)O(2). At much higher (0.5 mM), there is significant reduction level, no observed 5 mM 4 incubation. Exogenous NADPH enhanced similarly to These two agents, but not heparin, induced Ca(2+)-dependent an 80-kDa protein. (50 microM) approximately twofold cAMP, comparable bicarbonate, known activator soluble adenylyl cyclase sperm. This report suggests that relatively low are beneficial for capacitation, too high concentration inhibits process. We also conclude activates produce leading kinase A-dependent phosphorylation.