CALCIUM/CALMODULIN KINASE II AND HIS PARTICIPATION IN CAPACITATION OF Chinchilla lanigera SPERMATOZOA

APARICIO, J.D.; GRAMAJO BÜHLER, M.C.; BÜHLER M.I.

Tucumán

Jornada; XXVIII Annual meeting of biology asosociation of Tucumán; 2012

Asociación de Biología de Tucumán

The sperm of Chinchilla lanigera acquire fertilizing capacity through the capacitation process (CP) when changes the pattern of motility; allows acrosome reaction (RA), and select a subpopulation of gametes capable of fertilizing the egg. In the CP is increased [Ca2 +] i that activates various cell signaling pathways. In some species the calcium/calmodulin (Ca/CaM)-dependent protein kinase and Ca/CaM (CaMKII) has a major role in membrane fusion. The objective is to determine the role of the Ca/calmodulin-CaMKII pathway in the membrane events occurring during CP in epididymal sperm. Sperm were obtained by puncturing the cauda epididymis of sexually mature males. The samples were washed by centrifugation. The suspension was divided into six fractions. Four of them were preincubated with different concentrations of KN93, a CaMKII inhibitor, for 30 min. and incubated in Tyrode capacitation medium for 4 hs. The other two fractions were used as control. The CP was evaluated by the occurrence of RA induced by progesterone evidenced by Papannicolaou. The results indicate that the KN93 (5µM) produces an inhibition of RA. This effect is maintained without significant differences at higher concentrations (10, 20 and 40 mM). The reversibility assay indicated no cytotoxicity at the doses used. Blocking CaMKII has an inhibitory effect on CP, suggesting that this enzyme plays a regulatory role in the events involved in the CP.