O-7: Insulin Exerts a Prosurvival Effect on Human Spermatozoa via Mechanisms That Involve the Stimulation of Akt Phosphorylation

Background: The purpose of this study was to examine the impact of Insulin (INS) on human sperm function, in light of a recent proteomic analysis indicating that these cells express the INS receptor (INSR). Materials and Methods: We used Western blot and Immunocytochemical analyses. Results: Immunocytochemical analyses confirmed the presence of INSR in human spermatozoa and localized this receptor to the midpiece region of the sperm as well as the neck, postacrosomal, and principal piece of the sperm tail. Western blot analyses indicated that the prosurvival effect of INS on human spermatozoa involved the stimulation of Akt phosphorylatio. Conclusion: We conclude that INS is a prosurvival factor for human spermatozoa that prevents these cells from defaulting to an intrinsic apoptotic pathway associated with cell senescence. These findings have implications for preservation of sperm integrity in vivo and in vitro.