http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Induction of in vitro capacitation and acrosome reaction in equine spermatozoa
Experiments were conducted to investigate the efficacy of heparin, lysophosphatidylcholine (LPC), follicular fluid (FF), cumulus cells (CC) and zonae pellucidae (ZP) to induce in vitro capacitation and acrosome reaction in equine spermatozoa. Spermatozoa cultured with increasing concentrations of heparin did not differ in spontaneous (13%, all treatments) or LPC-induced acrosome reactions (26, 22, 26 & 23 in 0, 10, 50 & 100 ug heparin, respectively). The percentage of acrosome-reacted spermatozoa increased (P <.05) in a concentration- and time-dependent manner after treatment with LPC. Acrosome-reacted spermatozoa were maximal (P <.05) in number after 3.5 h (19, 26, 29, 38 & 49% in 0, 50, 100, 150 & 200 ug LPC treatments, respectively). Fetal calf serum (10%, FCS), 12.5, 25 and 50% FF did not differ in ability to support spontaneous (27, 20, 13 & 26%, respectively) or LPC-induced acrosome reactions (45, 36, 22 & 30%, respectively) after 5 h of culture. Spermatozoa incubated in the absence of protein had higher (P <.05) percentages of spontaneous (49%) and LPC-induced (57%) acrosome reactions. The percentage of viable spermatozoa after 5 h was less (P <.05) in diluents lacking protein (31%) and containing 50% FF (28%) as compared to spermatozoa in diluents containing FCS, 12.5 and 25% FF (55, 62 & 63%, respectively). Inclusion of CC in diluent and subsequent LPC challenge resulted in the highest (P <.05) percentage of acrosome-reacted spermatozoa (24%) following 4 h of culture as compared to spermatozoa unchallenged with LPC either in the absence (17%) or presence (13%) of CC. Spermatozoa challenged with LPC in the absence of CC did not result in a significant (P >.05) increase in the percentage of acrosome-reacted spermatozoa (20%). Spermatozoa challenged with heat-solubilized ZP (1 ZP/ul) had higher (P <.05) incidences of acrosome reactions (27%) as compared to unchallenged spermatozoa (17%) or LPC challenged spermatozoa (22%). In summary, these results indicate that heparin does not capacitate nor acrosome-react equine spermatozoa. Follicular fluid and CC support viability and capacitation, while LPC and heat-solubilized ZP induce acrosome reactions. In addition, three to four hours of culture appear to be necessary for in vitro capacitation of equine spermatozoa.
"Major subject: Physiology of reproduction."