The Enzymatic Antioxidant System of Human Spermatozoa
Figure 5
Antioxidant defence against oxidative stress in human spermatozoa and effects of availability of intracellular concentrations of NADPH and/or GSH on the antioxidant protection in human spermatozoa. The insufficient supply of NADPH and/or GSH, due to inactivation of G6PDH and probably NADP-ICDH by H2O2, promotes the establishment of a stronger oxidative stress that produces enzymatic inactivation of SOD and the formation of sulfonated form of 2-Cys PRDXs and of PRDX6, thus becoming impossible to reactivate their activity to fight against high levels of ROS and conducting impairment of sperm function and infertility.
