title: Motility initiation of quiescent spermatozoa from rat caudal epididymis: effects of pH, viscosity, osmolality and inhibitors.
abstract: Non-motile spermatozoa freshly extruded from the rat caudal epididymis can be initiated to full motility immediately after diluting with 0.9% NaCl. The motility initiation was dependent on the pH, viscosity and osmolality of diluent. Diluent with pH 4 to 8 could optimally initiate the motility. Osmolality of most diluents suitable for the initiation was between 130 to 600 mOsm/kg. The motility initiation was inhibited by Hg2+ greater than Cu2+ greater than Cd2+, chlorpromazine, Triton X-100 and SDS. The following compounds showed essentially no inhibitory effect: EGTA, chlortetracycline, calcein, ruthenium red, phloridzin, myo-inositol and carnitine. The findings suggested that spermatozoa were kept in quiescence in the cauda epididymis not by the pH, osmolality, viscosity, myo-inositol, carnitine, Ca2+ or K+ of the caudal epididymal fluid. It was also suggested that motility initiation did not involve Ca2+, calmodulin and transport of Ca2+ or glucose across sperm membrane.
mesh_terms: D000818:Animals; D002104:Cadmium / Q000494:pharmacology; D002746:Chlorpromazine / Q000494:pharmacology; D003300:Copper / Q000494:pharmacology; D004822:Epididymis / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D008297:Male; D008628:Mercury / Q000494:pharmacology; D017830:Octoxynol; D009994:Osmolar Concentration; D011092:Polyethylene Glycols / Q000494:pharmacology; D051381:Rats; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013081:Sperm Motility / Q000187:drug effects; D014783:Viscosity
chemical_list: D002104:Cadmium; D012967:Sodium Dodecyl Sulfate; D011092:Polyethylene Glycols; D003300:Copper; D017830:Octoxynol; D008628:Mercury; D002746:Chlorpromazine