Studies on the origin of redox enzymes in seminal plasma and their relationship with results of in-vitro fertilization

Glutathione (GSH), GSH peroxidase (GPX), GSH reductase (GRD), superoxidedismutase (SOD) and catalase-like enzyme activity were quantified inseminal plasma from normozoospermic patients, men with known distal ductalocclusion, proven fathers and male partners of couples receiving in-vitrofertilization (IVF) treatment for both male and female causes. Glutathionewas non-detectable (< 2.5 microM) in seminal plasma. None of the enzymeactivities per unit volume were lower in semen from vasectomized men,suggesting that they did not originate substantially from the testis orepididymis. The strongest relationships between enzyme activities andaccessory gland markers were between zinc and GRD (r = 0.678), SOD (r =0.602) and GPX (r = 0.548), suggesting a largely prostatic origin of theseenzymes. Only weak relationships between accessory gland markers andcatalase-like activity suggested a multi-glandular source of this enzyme.There was no relationship between the activity of any of the enzymes in theIVF patients with their fertilization rates in vitro or the establishmentof pregnancy after IVF. Nor was there any correlation of enzyme activitywith the morphology and percentage of motile spermatozoa in semen or withthe percentage motility of spermatozoa immediately after swim-up or afterovernight incubation. These findings suggest that the protective enzymes inthe seminal plasma are contributed largely by the prostate and little bythe epididymis, and that in most cases of IVF, they have no major influenceon the outcome.