Effects of bicarbonate ions and pH on acquisition and maintenance of potential for motility in ayu, Plecoglossus altivelis Temminck et Schlegel (Osmeridae), spermatozoa

Citation
H. Ohta et al., Effects of bicarbonate ions and pH on acquisition and maintenance of potential for motility in ayu, Plecoglossus altivelis Temminck et Schlegel (Osmeridae), spermatozoa, AQUAC RES, 32(5), 2001, pp. 385-392
Citations number
17
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Aquatic Sciences
Journal title
AQUACULTURE RESEARCH
ISSN journal
1355-557X → ACNP
Volume
32
Issue
5
Year of publication
2001
Pages
385 - 392
Database
ISI
SICI code
1355-557X(200105)32:5<385:EOBIAP>2.0.ZU;2-R
Abstract
The effects of extracellular ions on the acquisition and maintenance of the potential for motility in the spermatozoa of the ayu, Plecoglossus altivel is Temmick et Schlegel (Osmeridae), were examined. Testicular spermatozoa a nd milt spermatozoa were obtained from fully matured males and diluted with buffered solution (BS, 20 mM HEPES-NaOH, pH 7.5). Testicular spermatozoa s howed a significantly low rate of motility (0.8 +/- 0.4%), whereas milt spe rmatozoa showed a high rate (89.4 +/- 2.1%). The spermatozoa were incubated with various isotonic media for 2 h, diluted with BS, and changes in the r ates of motility were then compared. When incubated for 2 h with artificial seminal plasma (ASP), corresponding in terms of ionic constituents to semi nal plasma buffered at pH 8.0, both spermatozoa showed a high rate of motil ity. Testicular spermatozoa acquired and milt spermatozoa maintained the po tential for motility in response to the HCO3- ion concentrations (between 0 and 20 mM) in the ASP. The differences in the pH of the ASP had a signific ant effect on the acquisition and maintenance of the potential for motility , and spermatozoa showed the highest rate of motility with the ASP at pH 8. 0 and 8.5. These results suggest that the quality of milt in the ayu san be regulated by controlling the concentration of bicarbonate and the pH of th e incubating media.