Alterations in mitochondria membrane potential and oxidative stress in infertile men: a prospective observational study.

OBJECTIVE To evaluate the mitochondrial membrane potential (MMP) of spermatozoa and its correlation with semen parameters and production of reactive oxygen species (ROS) in infertile men and healthy donors. DESIGN Controlled prospective study. SETTING Male infertility clinic, Glickman Urological Institute, The Cleveland Clinic Foundation, Cleveland, Ohio. PATIENT(S) Nineteen infertile men and 7 healthy volunteers. INTERVENTION(S) Standard semen analysis, assessment of MMP and ROS production in spermatozoa. The MMP was assessed by flow cytometry using the probe carbocyanine DiOC(6)(3) and ROS was measured with chemiluminescence assay using luminol. MAIN OUTCOME MEASURE(S) The results of MMP are reported as the median interquartile range (IQR) number of cells counted in different areas of fluorescence. Results of ROS measurement are expressed as x10(6) counted photons per minute per 20 million sperm (cpm). RESULT(S) The patients with abnormal semen parameters had a significantly lower MMP [1337.7 (1066.38, 1879.2)], and higher ROS [1.12 (0.26, 3.86)] than the donors [MMP: 2482.9 (2162.5, 3520.6)] and [ROS: 0.10 (0.01, 0.14)]. The MMP was positively correlated with sperm concentration (r = 0.62) and negatively correlated with the ROS produced (r = -0.45). CONCLUSION(S) Measuring MMP in spermatozoa provides useful information about a man's fertility potential. Increased ROS production by spermatozoa is associated with a decreased MMP.