title: Reactive oxygen-induced reactive oxygen formation during human sperm capacitation.
abstract: Physiological processes are often activated by reactive oxygen species (ROS), such as the superoxide anion (O(2)(*)(-)) and nitric oxide (NO*) produced by cells. We studied the interactions between NO* and O(2)(*)(-), and their generators (NO* synthase, NOS, and a still elusive oxidase), in human spermatozoa during capacitation (transformations needed for acquisition of fertility). Albumin, fetal cord serum ultrafiltrate, and L-arginine triggered capacitation and ROS generation (NO* and O(2)(*)(-)) and superoxide dismutase (SOD) and NOS inhibitors prevented all these effects. Surprisingly, capacitation due to exogenous NO* (or O(2)(*)(-)) was also blocked by SOD (or NOS inhibitors). Probes used were proven specific and innocuous on spermatozoa. Whereas O(2)(*)(-) was needed only for 30 min, the continuous NO* generation was essential for hours. Capacitation caused a time-dependent increase in protein tyrosine nitration that was prevented by SOD and NOS inhibitors, suggesting that O(2)(*)(-) and NO*. also act via the formation of ONOO(-). Spermatozoa treated with NO* (or O(2)(*)(-)) initiated a dose-dependent O(2)(*)(-) (or NO*) production, providing, for the first time in cells, a strong evidence for a two-sided ROS-induced ROS generation. Data presented show a close interaction between NO* and O(2)(*)(-) and their generators during sperm capacitation.
authors.affiliation: Urology Research Laboratory, McGill University Hospital Centre at Royal Victoria Hospital, QC, Canada. edelamirande@yahoo.com
authors.forename: Eve
authors.initials: E
authors.lastname: de Lamirande
authors.forename: Geneviève
authors.initials: G
authors.lastname: Lamothe
mesh_terms: D020101:Acrosome Reaction / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D001120:Arginine / Q000502:physiology; D001798:Blood Proteins / Q000502:physiology; D003994:Bucladesine / Q000378:metabolism; D002417:Cattle; D002474:Cell-Free System; D002478:Cells, Cultured; D005260:Female; D005312:Fetal Blood / Q000502:physiology; D006801:Humans; D006834:Hydrazines / Q000494:pharmacology*; D007231:Infant, Newborn; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000737:chemistry / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D030421:Peroxynitrous Acid / Q000737:chemistry / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D011247:Pregnancy; D012710:Serum Albumin, Bovine / Q000502:physiology; D013075:Sperm Capacitation / Q000187:drug effects / Q000502:physiology*; D013094:Spermatozoa / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism
chemical_list: D001798:Blood Proteins; D006834:Hydrazines; D013481:Superoxides; D030421:Peroxynitrous Acid; D012710:Serum Albumin, Bovine; D009569:Nitric Oxide; D014443:Tyrosine; D003994:Bucladesine; C084012:1,1-diethyl-2-hydroxy-2-nitrosohydrazine; D001120:Arginine; D019001:Nitric Oxide Synthase; D013482:Superoxide Dismutase; D019331:NG-Nitroarginine Methyl Ester