THE INFLUENCE OF SERA, FOLLICULAR FLUIDS AND SEMINAL PLASMA ON HUMAN SPERM ZONA-PELLUCIDA BINDING

The purpose of this study was to assess the influence of male, female and fetal cord sera, follicular fluid, and seminal plasma on human spe rm-zona pellucida binding, using the hemizona assay, Steroids, gonadot rophins, growth hormone and prolactin concentrations in follicular flu id and sera mere also analysed. The influence of follicular fluid (10 or 50%, v/v) and sera (10%) on sperm-zona pellucida binding was invest igated by supplementing the sperm processing medium as well as the spe rm-hemizona incubation medium, Different seminal plasma concentrations (1 or 10%) were added to the sperm-hemizona incubation medium. Supple mentation with 10% day 3 donor serum was used as a control throughout experimentation, Although supplementation with male sera and fetal cor d serum exerted a stimulatory effect (36 and 90% respectively; P < 0.0 29) on sperm-zona pellucida binding, hemizona indices obtained with ad dition of male sera, fetal cord serum and sera obtained from sub-ferti le in-vitro fertilization (IVF) patients on day 12 of their menstrual cycle did not differ significantly (P > 0.05). Final progesterone conc entrations in sperm-zona pellucida incubation media (10% follicular fl uid supplementation), which ranged from 0.788 to 3.85 mu g/ml, enhance d sperm binding to the zonae by >100% (P < 0.02). The utilization of f ollicular fluid (10%) as a natural physiological stimulus to enhance s perm-zona pellucida binding in an IVF setting is recommended. The pres ence of seminal plasma in the sperm-zona pellucida incubation media sh owed no beneficial effect on the binding ability of sperm, and can be viewed as an unfavourable substance in the proximity of the oocyte.