PROLONGATION AND IMPROVEMENT OF PROSTASOME PROMOTIVE EFFECT ON SPERM FORWARD MOTILITY

Prostasomes isolated from human seminal plasma stimulated the forward motility of buffer-washed, and therewith immobilised, normal human spe rmatozoa in a dose- and time-related fashion. Albumin exhibited a simi lar capacity for stimulation. Combining prostasomes with 5 mmol/l of a ny of the hexoses fructose, glucose or mannose (but not galactose) res ulted in a prolongation and improvement of the effect by prostasomes ( or albumin) for the first 150 min. Hence, a dose-response effect at 60 and 120 min was obtained by prostasomes on sperm forward motility pro vided 5 mmol/l of fructose was present - otherwise not. Many substance s besides the hexoses were examined for possible positive effects on s perm forward motility in concert with prostasomes with no additional e ffect. Enrichment of optimum concentrations of prostasomes and glucose with 2 mmol/l of adenine stimulated further the velocity parameters o f the spermatozoa over time. The effect of adenosine was less evident under these conditions. Experiments carried out with prostasomes in th e presence of divalent cations or chelators suggested that magnesium i ons are essential for sperm forward motility. There appeared to be a s afety margin concerning calcium ions, and zinc ions did not seem to be primarily involved in sperm forward motility in the presence of prost asomes.