Participation of LDH in capacitation and acrosome reaction in porcine sperm

PEREYRA V; RODRIGUEZ PC; BREININGER E

Jornada; XVI Jornadas Anuales de la Sociedad Argentina de Biología; 2014

The aim of this study was to determine the activity of lactate dehydrogenase (LDH; 1.1.1.27) and evaluate its participation in capacitation and acrosome reaction (AR) in porcine spermatozoa. The activity of LDH was determined spectrophotometrically at 340 nm, during 3 minutes, at 37°C. Enzyme unit (U) was defined as the amount of LDH that catalyzes the oxidation of 1 µmol of NADH/min. Capacitation and AR were determined, in the presence or absence of oxamate (competitive inhibitor of LDH; 10, 25 and 50 mM), by CTC technique and trypan blue combined with DIC, respectively. Sperm viability was evaluated by the eosin-nigrosin technique and motility was evaluated by optic microscopy, with a thermal stage. Enzyme activity and capacitation and AR percentages were analysed by ANOVA and Bonferroni test. The activity of LDH was 3,40±1,21 U/1010 sperrmatozoa and the specific activity was 5,02±1,66 U per mg protein. Capacitation and AR were significantly diminished by the addition of 50 mM and 25mM of oxamate, respectively without affecting sperm viability. Our results demonstrate the activity of LDH and its participation in capacitation and AR in porcine spermatozoa, indicating the importance of the fermentative pathway in these processes.