CHARACTERIZATION OF CANNABINOID RECEPTORS IN SPERMATOZOA FROM WILD-TYPE (WT) AND CB1 KO MICE: EVALUATION OF THE INVOLVEMENT OF CANNABINOID RECEPTORS IN SPERM CAPACITATION

RAQUEL MARÍA LOTTERO LECONTE; CARLOS AGUSTÍN ISIDRO ALONSO; SILVINA PEREZ MARTINEZ

Buenos Aires

Congreso; JOINT MEETING OF BIOSCIENCE SOCIETIES; 2017

SAIC, SAB, SAIB, SAA, SAB, SAFE, SAFIS, SAH, SAI, SAP

The endocannabinoid system, including endocannabinoids and cannabinoids receptors (ECRs) such as CB1, CB2, TRPV1, has been characterized in most mammalian spermatozoa and at least in boar, bovine and human, plays a crucial role in sperm function. Our previous results indicate the involvement of CB1 and TRPV1 in bovine sperm capacitation. Here we characterized the ECRs in spermatozoa from WT and CB1 (-/-) (KO) mice and investigated its possible activation in sperm capacitation in both groups. First, we analyzed abundance (by Western Blot) and localization (by immunocytochemistry) of ECRs in mice spermatozoa from KO or WT. CB2 and TRPV1 are present in KO and they are localized in the acrosomal region (A) (CB2), or in A and post acrosomal (PA) regions (TRPV1), similarly to WT mice. In addition, an increase of TRPV1 in PA region was found in capacitated spermatozoa from both mice groups.Subsequently, the involvement of ECRs in capacitation was evaluated in WT and KO mice spermatozoa. In vitro capacitation was performed in the presence of increasing concentrations of CB1, CB2 and TRPV1 antagonists and evaluated by analyzing the levels of phosphorylation of tyrosine residues (pY), an essential event associated with this process.Results indicated that: 1) the increase in pY levels was similar in capacitated spermatozoa of the two mice groups; 2) the incubation with a CB1 antagonist (10-10-10-9M) produced a partial decrease in pY in WT mice; 3) the incubation with a CB2 antagonist (10-10-10-8M) did not decrease the levels of pY in either WT or KO mice. 4) the incubation with a TRPV1 antagonist (10-8 M) decreased ¡­ 30 % of pY levels (p