title: Role of calcium on the initiation of sperm motility in the European eel.
abstract: Sperm from European eel males treated with hCGrec was washed in a calcium free extender, and sperm motility was activated both in the presence (seawater, SW) and in the absence of calcium (NaCl+EDTA), and treated with calcium inhibitors or modulators. The sperm motility parameters were evaluated by a computer-assisted sperm analysis (CASA) system, and changes in the [Ca(2+)]i fluorescence (and in [Na(+)]i in some cases) were evaluated by flow cytometry. After sperm motility was activated in a medium containing Ca(2+) (seawater, SW) the intracellular fluorescence emitted by Ca(2+) increased 4-6-fold compared to the levels in quiescent sperm. However, while sperm activation in a Ca-free media (NaCl+EDTA) resulted in a percentage of motility similar to seawater, the [Ca(2+)]i levels did not increase at all. This result strongly suggests that increasing [Ca(2+)]i is not a pre-requisite for the induction of sperm motility in European eel sperm. Several sperm velocities (VCL, VSL, VAP) decreased when sperm was activated in the Ca-free activator, thus supporting the theory that Ca(2+) has a modulatory effect on sperm motility. The results indicate that a calcium/sodium exchanger (NCX) which is inhibited by bepridil and a calcium calmodulin kinase (inhibited by W-7), are involved in the sperm motility of the European eel. Our results indicate that the increase in [Ca(2+)]i concentrations during sperm activation is due to an influx from the external medium, but, unlike in most other species, it does not appear to be necessary for the activation of motility in European eel sperm.
authors.affiliation: Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera s/n. Edificio 7G, 46022 Valencia, Spain. Electronic address: mlpereig@dca.upv.es.
authors.forename: Luz
authors.initials: L
authors.lastname: Pérez
authors.affiliation: Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera s/n. Edificio 7G, 46022 Valencia, Spain.
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Vílchez
authors.affiliation: Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera s/n. Edificio 7G, 46022 Valencia, Spain.
authors.forename: Víctor
authors.initials: V
authors.lastname: Gallego
authors.affiliation: Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera s/n. Edificio 7G, 46022 Valencia, Spain.
authors.forename: Marina
authors.initials: M
authors.lastname: Morini
authors.affiliation: Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera s/n. Edificio 7G, 46022 Valencia, Spain.
authors.forename: David S
authors.initials: DS
authors.lastname: Peñaranda
authors.affiliation: Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera s/n. Edificio 7G, 46022 Valencia, Spain.
authors.forename: Juan F
authors.initials: JF
authors.lastname: Asturiano
mesh_terms: D000811:Anguilla / Q000502:physiology*; D000818:Animals; D015764:Bepridil / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D007476:Ionophores / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D012623:Seawater; D013081:Sperm Motility / Q000187:drug effects*; D013449:Sulfonamides / Q000494:pharmacology
chemical_list: D007476:Ionophores; D013449:Sulfonamides; D000001:Calcimycin; C017967:W 7; D015764:Bepridil; D002118:Calcium
keywords: Anguilla anguilla; Calcium/sodium exchanger; Flow cytometry; Intracellular ions; Sperm activation; Sperm kinetics; Sperm physiology