Low seminal zinc bound to high molecular weight proteins in asthenozoospermic patients: evidence of increased sperm zinc content in oligoasthenozoospermic patients [published erratum appears in Hum Reprod 1998 Jun;13(6):1750]

Total seminal zinc concentration, seminal zinc fraction bound to highmolecular weight proteins (HMW-Zn%) and zinc content in spermatozoa wereassayed in the ejaculates of 90 asthenozoospermic patients subdivided intotwo study groups: normoasthenozoospermics (group I: n = 50) andoligoasthenozoospermics (group II: n = 40). The zinc concentrations ofpatients were compared with those of a control group of donors showingnormal semen parameters. All samples were also investigated for their spermmembrane functional integrity by the hypo- osmotic swelling test (HOS). Theresults showed normal total zinc concentrations but very low HMW-Zn% values(P < 0.001) in seminal plasma of the two groups of asthenozoospermicpatients compared to the controls. Furthermore higher zinc amounts (P <0.001) were measured in spermatozoa of oligoasthenozoospermic patientscompared to group I and to the control group. Oligoasthenozoospermics alsodisplayed a lower HOS score (P < 0.001) compared to the other twogroups. These data suggest that the increased unbound seminal zinc couldcontribute to the decrease of sperm motility in normoasthenozoospermic andoligoasthenozoospermic patients. A further impairment in sperm motilitycould occur in the oligoasthenozoospermic patients where the increase ofseminal free zinc was followed by a major zinc uptake by spermatozoa. Thehigher intrasperm zinc content in these patients could be a reflection oftheir low sperm membrane functionality.