Oxidation of [U-14C] palmitic acid by cock spermatozoa.

When washed cock spermatozoa were incubated with [U-14 C] palmitic acid at 37 C for 2 hr under aerobic conditions, radioactivity was recovered as carbon dioxide indicating the fatty acid was oxidized. Little if any radioactivity was recovered as carbon dioxide when spermatozoa were killed by boiling, indicating the necessity for viable spermatozoa for the successful incorporation and oxidation of palmitic acid. To determine whether the oxidation of palmitic acid could serve as a source of energy for cock spermatozoa, ATP concentrations of spermatozoa were compared immediately following ejaculation and after 1,2, and 3 hr of incubation (37 C) with and without the addition of palmitic acid. At 1,2, and 3 hr of incubation, spermatozoa with palmitic acid as a substrate produced significantly (P less than or equal to .03) more ATP (2.62, 2.24, and 1.26 micrograms ATP/10(9) cells, respectively) than did spermatozoa without palmitic acid (1.62, 1.11, and .79 micrograms ATP/10(9) cells, respectively). These findings indicate that palmitic acid, one of the most abundant long-chain saturated fatty acids in cock spermatozoa, can be utilized as a source of energy.