Bicarbonate/CO2 induces rapid activation of phospholipase A2 and renders boar spermatozoa capable of undergoing acrosomal exocytosis in response to progesterone.
We tested whether capacitation, a phenomenon that renders spermatozoa capable of undergoing acrosomal exocytosis, may be completed rapidly after a short exposure to bicarbonate/CO2. We found that, in the presence of Ca2+, a 10-min exposure of boar spermatozoa to bicarbonate led to a partial activation of phospholipase A2, primed spermatozoa for a major subsequent activation of this enzyme upon stimulation with progesterone and furthermore rendered spermatozoa capable of undergoing exocytosis in response to this steroid. These results suggest that capacitation may be completed in a relatively short period of time and open up new possibilities for unravelling molecular mechanisms underlying this process.
Department of Development and Signalling, The Babraham Institute, Cambridge, UK.
E R
ER
Roldan
J M
JM
Vazquez
D000177:Acrosome / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D001639:Bicarbonates / Q000494:pharmacology*; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002245:Carbon Dioxide / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D004789:Enzyme Activation; D005089:Exocytosis / Q000187:drug effects; D007700:Kinetics; D008297:Male; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D011374:Progesterone / Q000494:pharmacology*; D013075:Sperm Capacitation; D013094:Spermatozoa / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D013552:Swine
D001639:Bicarbonates; D002245:Carbon Dioxide; D016718:Arachidonic Acid; D002110:Caffeine; D011374:Progesterone; D000242:Cyclic AMP; D010741:Phospholipases A; D054467:Phospholipases A2; D002118:Calcium