Metabolism of Pyruvate by Epididymal-Like Bovine Spermatozoa

Various factors affecting aerobic and anaerobic pyruvate metabolism by bovine spermatozoa were studied. With pyruvate as the sole exogenous substrate, DNP (10−4m) stimulated the respiration of ELC (epididymal-like sperm cells) of some bulls but had no effect on the respiration of others. DNP also depressed the aerobic pyruvate utilization and lactate accumulation by ELC. The disnmtation reaction, in which two molecules of pyruvate undergo dismutation to one molecule each of lactate, CO2, and acetate, was studied and was found to be stimulated anaerobically by both phosphate and sulfite. Phosphate, NAD, lipoic acid, and ATP stimulated the respiratory activity of ELC in the presence of pyruvate.