Increased Sperm Numbers in the Deferent Duct after Prostaglandin F 2α in Rabbits 1

Summary

Four experiments were conducted to test the influence of PGF_2α on the distribution of sperm in male rabbits. In the first, nine rabbits were anesthetized, one side of the reproductive tract was removed, and 5 mg PGF_2α was injected around the remaining testis and epididymis. Relative to the controls, the deferent duct contained more than twice as many sperm at 10, 30, or 60 min after PGF_2α. Results from the second trial showed that the deferent duct of rabbits did not accumulate sperm during 30 min under anesthesia without PGF_2α treatment, but deferent duct sperm were more than doubled at 30 min after 5 mg PGF_2α injected subcutaneously. In the third experiment, four unanesthetized rabbits injected subcutaneously three times (at 20-min intervals) with 10 mg PGF_2α had about threefold more deferent duct sperm and significantly fewer sperm in the head-body epididymis than four saline-injected control rabbits. Relative to ten controls in the final experiment, after five sc injections of 1 mg PGF_2α at 12-min intervals, ten rabbits had more sperm in the paired deferent ducts (70 vs 224 × 10⁶, P <0.01), a greater percentage of the total excurrent duct sperm in the deferent duct (3.6 vs 10.3%, P <0.01), and more deferent duct sperm per 100 × 10⁶ testicular sperm (18 vs 58, P <0.01). We conclude that PGF_2α causes increased numbers of sperm in the deferent duct, possibly by increasing the rate of movement of sperm out of the epididymis.