Migration of hamster sperm within capillaries: effect of agents elevating cyclic AMP

Semiautomated capillary scanning was used to quantitate the migratory rate of hamster caudal epididymal (HCE) sperm populations from undiluted exudates into various defined media. The populations migrated through calcium-containing Tyrode's solution four times more rapidly than they did through buffered-glucose fortified saline or isotonic sucrose. This difference was partially eliminated by the addition to the saline or sucrose of the motility inducers, calcium ion or cyclic adenosine monophosphate (cAMP), and completely eliminated by the additional presence of the motility amplifiers, caffeine or spermine. The addition of the motility amplifiers, caffeine or spermine, alone to either calcium-saline or Tyrode's solution greatly stimulated the microscopically judged vigor of motility. However, this increase in flagellar activity was not coupled to increased forward velocity. Instead, as in the case of capacitated HCE sperm, the activation of motility resulted in significantly reduced forward velocities. Thus, it appears that under certain conditions caffeine, spermine, or capacitation can elevate sperm cAMP concentrations above those optimal for maximal forward progression.