Measurements of bovine sperm velocities under true anaerobic and aerobic conditions

Velocities of bovine spermatozoa in a medium containing glucose were simila r under true anaerobic and aerobic conditions. Spermatozoa were not able to sustain motility under anaerobic conditions when glycolysis was inhibited, but regained motility when re-aerated. This demonstrates that immobilisati on was due to lack of oxygen and that conditions under which motility was a nalysed were truly anaerobic. Sperm motility parameters were not significan tly different in the presence and absence of 4 mu M antimycin A and 4 mu M rotenone when glucose was present in the medium. After each incubation, fun ctionality of sperm mitochondria was assayed by washing sperm into the medi um which supported respiration but not glycolysis, and motility was visuall y assessed. All sperm samples were highly motile in this medium indicating that their mitochondria were functional. When glycolysis was inhibited, ant imycin and rotenone abolished sperm motility immediately after addition. Bo vine sperm can maintain similar levels of motility aerobically and anaerobi cally if a glycolysable substrate is available. Available data on bovine sp erm energetics support this view. (C) 1999 Elsevier Science B.V. All rights reserved.