Sodium-potassium-ATPase in boar spermatozoa.

摘要

Na+K+ATPase has been implicated in intracellular signaling and ion transport mechanisms in capacitating bull spermatozoa. The presence and location of Na+K+ATPase in boar spermatozoa are identified here for the first time. The head plasma membrane (HPM) was isolated from boar spermatozoa by nitrogen cavitation and differential centrifugation and confirmed pure by enrichment of the marker enzymes acid and alkaline phosphatase (218+/-23 and 245+/-38% enriched, respectively, versus whole spermatozoa). Western immunoblotting detected the isoform subunits alpha3, beta1, beta2, beta3 and alpha1 in whole boar spermatozoa and HPM. Immunofluorescence of intact and permeabilized spermatozoa localized alpha3 to the exterior surface of the post-equatorial HPM and the outer leaflet of the outer acrosomal membrane. beta1 and beta3 were localized to the acrosomal region of the HPM, and alpha1 and beta2 localized along the apical ridge. The specialized location of Na+K +ATPase supports further investigation into a possible functional role in boar spermatozoa.