title: Implication that potassium flux and increase in intracellular calcium are necessary for the initiation of sperm motility in salmonid fishes.
abstract: Flux of K+ and changes in intracellular Ca2+ in the sperm of salmonid fishes were measured with spectrophotometry, ion electrode, microscopic fluorometry, and radioisotope accumulation. Release of K+ occurred at the initiation of sperm motility which is induced by decrease in external K+ and the K+ efflux and sperm motility were inhibited by K+ channel blockers. Intracellular Ca2+ increased within a short period in K(+)-free condition, and the accumulation of 45Ca in sperm cells was higher in motile sperm than that in immotile sperm. The efflux of K+ and the increase in intracellular Ca2+ were suppressed when external K+ concentration increased, i.e., sperm remained immotile. These results suggest that efflux of K+ through K+ channel and subsequent increase in intracellular Ca2+ are prerequisite for the initiation of sperm motility.
authors.affiliation: Department of Biology, Faculty of Science, Toho University, Funabashi, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Tanimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Kudo
authors.forename: T
authors.initials: T
authors.lastname: Nakazawa
authors.forename: M
authors.initials: M
authors.lastname: Morisawa
mesh_terms: D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D001464:Barium / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D016257:Fura-2; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008856:Microscopy, Fluorescence; D017686:Oncorhynchus mykiss; D009947:Organotin Compounds / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism* / Q000494:pharmacology; D026902:Potassium Channel Blockers; D012474:Salmon; D013081:Sperm Motility; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology*; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology
chemical_list: D009947:Organotin Compounds; D026902:Potassium Channel Blockers; D013757:Tetraethylammonium Compounds; D001464:Barium; D019789:Tetraethylammonium; D015761:4-Aminopyridine; C007567:triphenyltin hydroxide; D011188:Potassium; D002118:Calcium; D016257:Fura-2