The Motility and Aerobic Metabolism of Spermatozoa in Laboratory Animals with Special Reference to the Effects of Cold Shock and the Importance of Calcium for the Motility of Hamster Spermatozoa1

Abstract

The metabolism and motility of epididymal spermatozoa of the hamster, rat, guinea pig, and rabbit have been studied in the presence or absence of male accessory secretions. The metabolic activity of hamster spematozoa was about three times higher than that of rat spermatozoa. In both Ringer’s solution and in 0.85% NaCl solution the motility of hamster epididymal spermatozoa was greatly decreased for about 4 hr and recovered again in the course of incubation at 37 C. This reaction seemed to be specific to hamster spermatozoa and was never observed in rat, guinea pig, and rabbit spermatozoa. The motility and respiration of hamster spermatozoa were depressed by the presence of fresh seminal vesicular fluid. However, the presence of fluids from fresh dorsal prostate or from the seminal vesicle stored at 5 C for 2 days stimulated both respiration and motility. In contrast, the presence of fluid from the ventral prostate depressed both oxygen uptake and motility of spermatozoa. A factor which can sensitize the epididymal spermatozoa to cold shock seemed to be present in the male accessory glands although the location of this factor may differ in different species. Hamster epididymal spermatozoa stopped forward motility immediately after being mixed with calcium-free solutions, although short-wave flagellation continued for a long while. In contrast, progressive motility of long duration was observed in the epididymal spermatozoa of the rat, mouse and rabbit either with or without calcium chloride in the media. The effect of calcium on the motility of hamster spermatozoa is specific to the spermatozoa themselves and is not influenced by accessory secretions. The minimal concentration of calcium chloride for the maintenance of normal motility of hamster spermatozoa was found to be 0.001 M in the medium. The motility of hamster spermatozoa was maintained by the addition of glucose, fructose, fructose-1,6-phosphate, sodium acetate, or even ATP only when calcium chloride and sodium bicarbonate were present in the medium. Calcium chloride had no effect on the oxygen uptake and fructose utilization by hamster spermatozoa, but only the presence of calcium chloride would maintain progressive motility for 12 hr. It appears that there is an intrinsic difference in the mechanism of motility of spermatozoa of the hamster and those of other species although there is little evidence to show a difference in their metabolic patterns.