In vitro tests for essential sperm functions using the phyto-oestrogen genistein as a test substance

Sperm motility, binding of spermatozoa to the zone pellucida and induction of the acrosome reaction are prerequisites for successful oocyte fertilizat ion. Examination of the physiological and nonphysiological effects of parti cular compounds on sperm functions requires high-quality in vitro test syst ems. In this short methodological overview, a reliable combined in vitro te st system with bovine gametes is described. The purpose of the study was to evaluate whether aliquots of pooled post-thaw spermatozoa are suitable for examination of environmental substances that affect essential sperm functi ons. The combined test system includes a number of known methods for the as sessment of sperm vitality and motion parameters, acrosomal status, inducib ility of acrosome reaction and sperm-zona pellucida binding. First observat ions indicate that genistein inhibits the induction of acrosomal exocytosis and binding of spermatozoa. to the zona pellucida. Motility parameters and the viability of bovine spermatozoa were not affected by this substance. I t is concluded that genistein, a phyto-oestrogen which is abundant in sever al plants, can be used as a test substance for the evaluation of effects up on essential bovine sperm functions in vitro.