CALCIUM ROLE IN ACROSOME REACTION IN SPERMATOZOA OF Chinchilla lanigera

GRAMAJO BÜHLER MC; SANCHEZ TORANZO G.

Tafí del Valle

Jornada; XXXIV Jonadas Científicas; 2017

Asociación de Biología de Tucumán

The acrosome reaction (AR) is a synchronized and regulated event. It depends on the variations in the intracellular concentration of the calcium ion, due to the influx or mobilization of the cytosolic reserves. Calcium is capable of activating cascades of signal transduction,which requires proteins and enzymes such as calmodulin (CaM) and a kinase II (CaMKII). Male infertility is often due to the inability of gametes to respond to external / internal stimuli. The study of the participation, internal mobilization and calcium signaling pathways involved in the AR is an important contribution to the knowledge of the process. The objective of this work is to study the signaling pathways involved in the internal mobilization of calcium and the participation of the Ca2+ / CaM / CaMKII system in the AR in Chinchilla. The spermatozoa obtained from the tail of the epididymis of adult animals were capacitated (EC) in TH3 medium and the AR was induced with progesterone (P4) 20μM. The CDs were incubated with inhibitors of receptors for IP3 and ryanodine at different concentrations, evaluating the AR by staining with Coomassie Blue. CaM was immunolocalized in non capacitated sperm, EC and AR.Spermatozoa pretreated with Stelazine-Stz (CaMinh) and KN93 (CaMKIIinh) were exposed to P4. A decrease in AR % was observed in the samples treated with R-IP3 inhibitors. CaM undergoes relocation in EC and AR. The use of Stz yielded AR % higher than controls while the assays with KN93 did not show differences with the controls. The mobilization of Ca2+ from the reserves is done through the IP3 route. The Ca2+ / CaM / CaMKII system participates by relocating CaM after capacitation and kinase II apparently prevents AR.