The fertilization process requires glucose in a number of species (mouse; rat; human ). In the mouse, the analysis of the sequence of events leading to fertilization in vitro has indicated that glucose is essential for the penetration of the zona pellucida and for the fusion of the gametes. The failure to penetrate the zona pellucida in the absence of glucose has been attributed to the altered hyperactivated motility of the sperm. In contrast to hyperactivated motility, sperm capacitation and the acro-some reaction are necessary steps for the spermatozoa to fuse with the oocytes. buy birth control online
Although the influence of glucose on the acrosome reaction in the mouse is uncertain, spermatozoa that have acrosome-reacted spontaneously in the presence of glucose lose their ability to fuse with the oolemma after the removal of this hexose. This suggests that, in addition to the acrosome reaction, a glucose-regulated event influences the ability of the spermatozoon to fuse with the oocyte. Despite the abundant studies on gametes and fertilization, the precise role of glucose in specific gamete functions and, in particular, in those involved in sperm-oocyte fusion, have not yet been identified.