title: Cadmium inhibits motility, activities of plasma membrane Ca(2+)-ATPase and axonemal dynein-ATPase of human spermatozoa.
abstract: Cd(2+) has been associated with decreased sperm motility in individuals exposed to this element, such as smokers. Among other factors, this lowered motility could be the result of inhibition exerted by Cd(2+) on the activity of the sperm ATPases associated with sperm motility. In this study, we evaluated the plasma membrane Ca(2+)-ATPase and the axonemal dynein-ATPase activities as well as sperm motility, in the presence of different free Cd(2+) concentrations in the assay media. It was found that spermatozoa incubated for 5 h in a medium containing 25 nm free Cd(2+) showed a significant inhibition of progressive motility, reaching values even lower at higher Cd(2+) concentrations. In addition, it was found that the activity of the plasma membrane Ca(2+)-ATPase reached maximal inhibition at 50 nm free Cd(2+), with a K50% inhibition of 18.3 nm free Cd(2+). The dynein-ATPase activity was maximally inhibited by 25 nm free Cd(2+) in the assay medium, with a K50% inhibition of 11.3 nm Cd(2+). Our results indicate that the decreased activity of the sperm ATPases might have a critical importance in the biochemical mechanisms underlying the decreased sperm motility of individuals exposed to Cd(2+).
authors.affiliation: Laboratorio de Bioenergética Celular, Centro de Biofísica y Bioquímica (CBB), Instituto Venezolano de Investigaciones Científicas (IVIC), Caracas, Venezuela.
authors.forename: R
authors.initials: R
authors.lastname: Da Costa
authors.affiliation: Laboratorio de Bioenergética Celular, Centro de Biofísica y Bioquímica (CBB), Instituto Venezolano de Investigaciones Científicas (IVIC), Caracas, Venezuela.
authors.forename: D
authors.initials: D
authors.lastname: Botana
authors.affiliation: Laboratorio de Bioenergética Celular, Centro de Biofísica y Bioquímica (CBB), Instituto Venezolano de Investigaciones Científicas (IVIC), Caracas, Venezuela.
authors.forename: S
authors.initials: S
authors.lastname: Piñero
authors.affiliation: Laboratorio de Bioenergética Celular, Centro de Biofísica y Bioquímica (CBB), Instituto Venezolano de Investigaciones Científicas (IVIC), Caracas, Venezuela.
authors.forename: F
authors.initials: F
authors.lastname: Proverbio
authors.affiliation: Laboratorio de Bioenergética Celular, Centro de Biofísica y Bioquímica (CBB), Instituto Venezolano de Investigaciones Científicas (IVIC), Caracas, Venezuela.
authors.forename: R
authors.initials: R
authors.lastname: Marín
mesh_terms: D056444:Axonemal Dyneins / Q000378:metabolism*; D002104:Cadmium / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000633:toxicity*; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D057075:Enzyme Assays; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D013081:Sperm Motility / Q000187:drug effects*; D013094:Spermatozoa / Q000187:drug effects* / Q000201:enzymology
chemical_list: D002104:Cadmium; D056444:Axonemal Dyneins; D000252:Calcium-Transporting ATPases
keywords: Ca-ATPase; cadmium; dynein-ATPase; human sperm motility