title: Acrosome reaction in bovine spermatozoa: role of reactive oxygen species and lactate dehydrogenase C4.
abstract: After capacitation, mammalian spermatozoa accomplish the acrosome reaction (AR), a well-controlled exocytosis process crucial to fertilize mature oocytes that involves several protein kinases such as protein kinase A (PKA), C (PKC), and tyrosine kinase (PTK). Reactive oxygen species (ROS) are involved in both bovine sperm capacitation and AR. Lactate dehydrogenase C4 (LDH-C4) was associated with bovine and mouse sperm capacitation. Our aims were to study the participation of LDH-C4 to contribute with the status redox required for AR and the role of ROS in the regulation of PKA, PKC, and PTK involved in the exocytotic event. Sodium oxamate, an inhibitor of LDH-C4, prevented the AR induced by lysophosphatidylcholine (LPC) or NADH. Hydrogen peroxide promoted and superoxide dismutase (scavenger of superoxide), catalase (scavenger of hydrogen peroxide), diphenyleneiodinum, diphenyliodonium, cibacron blue, and lapachol (inhibitors of NADPH oxidase) prevented the AR, suggesting that ROS and a sperm oxidase are involved in the AR induced by these compounds. Inhibitors of PKA, PKC, and PTK also prevented the AR induced by LPC or NADH, suggesting the involvement of these kinases in the process. These results suggest that LDH-C4 may participate in the regulation of the redox status required to achieve the AR in bovine spermatozoa and that ROS are key elements in the regulation of protein kinases associated with the AR process.
authors.affiliation: Area of Biochemistry, School of Veterinary Sciences, University of Buenos Aires, Buenos Aires, Argentina. coflaher@yahoo.com
authors.forename: C
authors.initials: C
authors.lastname: O'Flaherty
authors.forename: E
authors.initials: E
authors.lastname: Breininger
authors.forename: N
authors.initials: N
authors.lastname: Beorlegui
authors.forename: M T
authors.initials: MT
authors.lastname: Beconi
mesh_terms: D000177:Acrosome / Q000201:enzymology*; D020101:Acrosome Reaction / Q000187:drug effects / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D001713:Biphenyl Compounds / Q000494:pharmacology; D002374:Catalase / Q000494:pharmacology; D002417:Cattle / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008244:Lysophosphatidylcholines / Q000494:pharmacology; D008297:Male; D009285:Naphthoquinones / Q000494:pharmacology; D009861:Onium Compounds / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013075:Sperm Capacitation / Q000502:physiology; D013094:Spermatozoa / Q000378:metabolism* / Q000502:physiology; D013482:Superoxide Dismutase / Q000494:pharmacology; D014227:Triazines / Q000494:pharmacology
chemical_list: D001713:Biphenyl Compounds; D007527:Isoenzymes; D008244:Lysophosphatidylcholines; D009285:Naphthoquinones; D009861:Onium Compounds; D017382:Reactive Oxygen Species; D014227:Triazines; C031291:diphenyliodonium; C012842:Cibacron Blue F 3GA; C007517:diphenyleneiodonium; C008252:lapachol; D006861:Hydrogen Peroxide; D007770:L-Lactate Dehydrogenase; C409673:lactate dehydrogenase C4; D002374:Catalase; D013482:Superoxide Dismutase; D011505:Protein-Tyrosine Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C