title: Temporary inhibition of the initiation of motility of demembranated hamster sperm by high concentrations of ATP.
abstract: ATP is obligatory for sperm movement. When sperm from the hamster cauda epididymis were washed and exposed to a demembranation and re-activation medium containing 0.5 or 1 mM ATP, the maximal % motility was attained almost immediately. Increasing the ATP concentration to 3 mM caused a 5 min delay in development of maximal re-activation and a change in the beating pattern as indicated by a decrease in the % of forward progressing sperm, decreased linear velocities but unchanged curvilinear velocities. The inhibition of motility initiation by 3 mM ATP was abolished either by the inclusion of trypsin (50 ng/ml) or by a brief pre-incubation of the sperm in the demembranation and reactivation medium before the addition of ATP. However, the beneficial effect of pre-incubation was prevented if trypsin inhibitor was present. This indicates that the inhibition by ATP acts via a trypsin-sensitive regulatory system, and suggests that an endogenous protease activity is necessary to overcome this. Re-activation of sperm from the caput epididymis by all three concentrations of ATP showed similar lag periods which could also be diminished by pre-incubation or trypsin. The results suggest that, in addition to developing their motile capacity during maturation in the epididymis, sperm exonemes change their sensitivity to ATP concentrations.
mesh_terms: D000255:Adenosine Triphosphate / Q000502:physiology*; D000818:Animals; D002462:Cell Membrane / Q000502:physiology; D006224:Cricetinae; D008297:Male; D008647:Mesocricetus; D017830:Octoxynol; D011092:Polyethylene Glycols; D013079:Sperm Maturation; D013081:Sperm Motility
chemical_list: D011092:Polyethylene Glycols; D000255:Adenosine Triphosphate; D017830:Octoxynol