Calcium signaling in human spermatozoa

DE BLAS GA; BRANHAM MT; TREVIÑO C; SOLÍS A; TOMES CN; MAYORGA L; DARSZON A

Mendoza

Congreso; XLVIII Reunión Anual Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular (SAIB); 2012

Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular (SAIB)

Calcium and cAMP signaling plays a pivotal role in spermphysiology, being intimately involved in the regulation ofcapacitation, hyperactivation and acrosome reaction. In a previousreport we have proposed that the cAMP analogue 8-(pchlorophenylthio)-2´-O-methyladenosine-3´, 5´-cyclicmonophosphate (8-pCPT-2´-O-Me-cAMP) elicits intracellularcalcium release in human sperm. Intracellular calcium stores play acentral role in the regulation of cellular [Ca2+]i and in thegeneration of complex [Ca2+] signals such as oscillations andwaves. The aim of this study was to investigate the calcium storesand calcium channels involved in the 8-pCPT-2´-O-Me-cAMPpathway in human spermatozoa.We used real time dynamic assays -with high speed and spatial resolution- and fluorescent calciumsensors. To asses this, capacitated human sperm were loaded withFluo3-AM, then incubated in a calcium-free medium and treatedwith different agonist of the AR (8-pCPT-2´-O-Me-cAMP,progesterone and recombinant human ZP3). We found that all ARinducers triggered spatial distribution of Ca2+and using a kineticassay we studied the dynamics and direction of the calcium wave.Our results indicate that 8-pCPT-2´-O-Me-cAMP, progesterone andZP3 induce a calcium wave that starts in the posterior neck regionand propagates to the acrosome region.