Properties of human epididymal sperm obtained from an alloplastic spermatocele: motility assessment and penetration of zona-free hamster oocytes in the presence and absence of caffeine.

Sperm were collected over a period of months from a human alloplastic spermatocele implanted at the corpus/caudal epididymal junction and were evaluated for their maturity, motility, and ability to capacitate and acrosome react, as assessed by the hamster zona-free oocyte sperm penetration assay (SPA). A mean of 11 X 10(6) sperm were obtained with each aspiration, with 34% to 40% being mature, normal forms. Motility was poor; 15% +/- 5% showing nonprogressive movement. SPA results were 22% +/- 3% oocyte penetration. Addition of 7.5 mM caffeine markedly enhanced motility and improved the SPA results. After 30 minutes' exposure, the motility was 45% +/- 5%, with all spermatozoa exhibiting progressive movement. This stimulation was maintained over a 24-hour period. When caffeine was present during the 2-hour preincubation for the SPA, penetration rates increased to 50% +/- 10% (P less than 0.05). These results demonstrate that the poor-quality sperm retrieved from a human alloplastic spermatocele can be improved with exogenous stimulation and suggest that their fertilizing capacity may be enhanced by this treatment.