Roles of extracellular Ca2+in the occurrence of full-type hyperactivation in boar ejaculated spermatozoa pre-incubated to induce the cAMP-triggered events

摘要: There are species differences in the regulatory system for sperm capacitation and subsequent hyperactivation between livestock laboratory animals. In spermatozoa, it is poorly understood when how extracellular Ca(2+) necessary hyperactivation, although has been demonstrated that [Ca(2+) ]i increase indispensable to occurrence of hyperactivation. this study, we examined necessity initiation maintenance then sought possible target molecule was involved boar spermatozoa. Boar ejaculated spermatozoa were pre-incubated with a cell-permeable cyclic adenosine monophosphate (cAMP) analog 'cBiMPS' without CaCl2 induce cAMP-triggered events including capacitation-associated changes. Subsequently, they incubated used motility assessment. Many after incubation exhibited full-type which characterized by high-amplitude extremely asymmetrical beating whole middle piece principal piece. The required millimolar concentration medium. However, medium less than as hyperactivated barely affected -chelating reagent. On other hand, pre-treatment inhibitor -dependent protease 'calpain 1 2' clearly suppressed -induced influences on percentages motile Western blotting indirect immunofluorescence showed distribution calpain 2 pieces beating. basis these results, conclude initiation, but not beforehand undergo Moreover, suggest involvement intracellular signal transduction leading