Effect of ornidazole on fertility of male rats: inhibition of a glycolysis-related motility pattern and zona binding required for fertilization in vitro

Abstract

The effects of the male antifertility agent ornidazole on glycolysis as a prerequisite for fertilization were investigated in rats. Antifertility doses of ornidazole inhibited glycolysis within mature spermatozoa as determined from the lack of glucose utilization, reduced acidosis under anaerobic conditions and reduced glycolytic enzyme activity. As a consequence, cauda epididymidal spermatozoa from ornidazole-fed rats were unable to fertilize rat oocytes in vitro, with or without cumulus cells, which was not due to transfer of an inhibitor in epididymal fluid with the spermatozoa. Under IVF conditions, binding to the zona pellucida was reduced in spermatozoa from ornidazole-fed males and the spermatozoa did not undergo a change in swimming pattern, which was observed in controls. The block to fertilization could be explained by the disruption of glycolysis-dependent events, since reduced binding to the zona pellucida and a lack of kinematic changes were demonstrated by control spermatozoa in glucose-free media in the presence of respiratory substrates. The importance of glycolysis for binding to, and penetration of, the zona pellucida, and hyperactivation in rats is discussed in relation to the glycolytic production of ATP in the principal piece in which local deprivation of energy may explain the reduced force of spermatozoa from ornidazole-fed males.

Antispermatogenic effects of aqueous ethanolic extract of Hymenocardia acida stem bark in Wistar rats

“…The decreases in absolute or relative organ weights as observed in the present study are suggestive of biosensitivity to H. acida extract (Raji et al, 2005). The reduction in testicular weight might be attributable to a direct effect of the extract on the histoarchitecture of the testis (Figure 4) as reported by other investigators (Bone et al, 2000) leading to depletion of germinal or spermatogenic elements and ultimately to disruption of spermatogenesis. The seminiferous tubules make up about 90% of the wet weight of the testis (Mishra and Singh, 2008).…”

A novel pyruvate kinase (PK-S) from boar spermatozoa is localized at the fibrous sheath and the acrosome

“…The mechanisms by which glycolysis affects fertility of spermatozoa remain still not clear. Glycolysis is involved in capacitation by stimulation of protein tyrosine phosphorylation (Urner & Sakkas 2003) and/or in providing the principal piece of the flagellum with ATP particularly for the vigorous whiplash motility (hyperactivity) that produces the thrust to penetrate the zona pellucida (Yanagimachi 1994, Bedford 1998, Bone et al 2000, Williams & Ford 2001. Whether local glycolytic ATP-production is essential for sperm motility or can be substituted by other means has comprehensively been discussed by Ford (2006).…”

Regulatory properties of 6-phosphofructokinase and control of glycolysis in boar spermatozoa

“…Spermatozoa from rat epididymis proved unable to fertilize eggs in vitro if either glucose was omitted from (Niwa & Iritani 1978) or substances blocking glycolysis were added to the medium (Bone et al 2000). Fertilization seems to require hyperactivity, a special form of sperm motility, which (unlike progressive motility) can only be observed if glycolysis is not hampered (Fraser & Quinn 1981).…”