Membrane-associated adenylate cyclase modulates lactate dehydrogenase and creatine kinase activity required for bovine sperm capacitation with hyaluronic acid

CÓRDOBA M; FERNÁNDEZ S

ANIMAL REPRODUCTION SCIENCE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2017 p. 80 - 87

0378-4320

Hyaluronic acid, as well as heparin, is a glycosaminoglycan present in the female genital tract of cattle. The aim of this study was to evaluate oxidative metabolism and intracellular signals mediated by a membrane-associated adenylate cyclase, during sperm capacitation with hyaluronic acid and heparin, in cryopreserved bull sperm. The membrane-associated adenylate cyclase inhibitor, 2´,5´-dideoxyadenosine, was used in the present study. Lactate dehydrogenase (LDH) and creatine kinase (CK) activities and lactate concentration were determined spectrophotometrically in the incubation medium. Capacitation and acrosome reaction were evaluated by chlortetracycline technique, while plasma membrane and acrosome integrity were determined by trypan blue stain/differential interference contrast microscopy. Heparin capacitated samples had a significant decrease in LDH and CK activities, while in hyaluronic acid capacitated samples LDH and CK activities both increased compared to control samples. A significant increase in lactate concentration in the incubation medium occurred in hyaluronic acid-treated sperm samples compared to heparin treatment, indicating this energetic metabolite is produced during capacitation. The LDH and CK enzyme activities and lactate concentrations in the incubation medium were decreased with 2´,5´-dideoxyadenosine treatment in hyaluronic acid samples. The membrane-associated adenylate cyclase inhibitor significantly inhibited heparin-induced capacitation of sperm cells, but did not completely inhibit hyaluronic acid capacitation. Therefore, heparin and hyaluronic acid are physiological glycosaminoglycans capable of inducing in vitro capacitation in cryopreserved bull sperm, stimulating different enzymatic pathways and intracellular signals modulated by a membrane-associated adenylate cyclase.