To permit gamete fusion, glucose must be metabolized because non-metabolizable glucose analogues (L-glucose, 3-O-methylglucose, 2-deoxyglucose) are unable to support this process. In contrast to the metabolism of oocytes, which does not appear necessary for this event, the metabolism of spermatozoa may be linked to the fusion step. While it is well accepted that glucose metabolism through glycolysis provides energy to spermatozoa, the existence and the role of the pentose phosphate pathway (PPP) have not been unequivocally demonstrated in spermatozoa. The main function of the PPP is to generate NADPH, which is required for reductive reactions, and to form ribose 5-phosphate for the synthesis of nucleic acids. The implication of NADPH in certain human sperm functions indicates that the PPP may be involved in successful fertilization. flovent inhaler
The main purpose of this study was therefore 1) to demonstrate the presence of a functional PPP in mouse spermatozoa and 2) to determine whether this pathway is implicated in the spermatozoa’s acquisition of competence to fuse and enter the oocyte.