THE INTERRELATION OF OXIDATIVE AND GLYCOLYTIC PROCESSES AS SOURCES OF ENERGY FOR BULL SPERMATOZOA

Abstract

The interrelation of oxidative and glycolytic processes in the metabolism of bull spermatozoa was studied with the following results. Bull spermatozoa in a medium containing no sugar retain motility only in the presence of air, indicating that oxygen is required for the utilization of the intracellular reserves. The results of chemical and respiration studies indicate that the intracellular reserves used by the oxidative process are phospholipids. During storage the phospholipid content of semen decreased. The decrease occurred also in sperm suspensions free of seminal fluid and here was lessened by the addition of glucose. The decrease in phospholipids paralleled the oxidative Utilization of intracellular reserves for the maintenance of motility. The rate of O2 consumption by bull spermatozoa in the presence of glucose was much less than the "endogenous" rate, which indicated a preferential utilization of glycolytic mechanisms as a means of obtaining energy for motility. Phospholipids are evidently the source of the intracellular reserve energy of spermatozoa; this energy is obtained by oxidative processes and spermatozoa preferentially obtain the energy for motility from the glycolysis of glucose or other glycolyzable sugars.