Coenzyme Q10 levels in human seminal fluid: diagnostic and clinical implications.

The levels of Coenzyme Q10 (CoQ10) were determined by HPLC in seminal fluid samples obtained from 77 patients who performed a standard semen analysis for infertility, previous phlogosis or varicocele. CoQ10 was determined in total seminal fluid (n = 60), in seminal plasma (n = 44) and in the cell pellet (n = 37). The molecule, in total fluid, showed a linear correlation with sperm count and motility. In the pellet of spermatozoa, a trend toward an inverse correlation between CoQ10 (expressed as ng/10(6) cells) and semen parameters could be observed. A different pattern was shown in varicocele patients, in whom, in total fluid, the correlation between CoQ10 and sperm count was preserved, but the one between CoQ10 and sperm motility was lacking; moreover, a higher proportion of CoQ10 was present in seminal plasma, and the inverse trend between cellular CoQ10 and sperm count and motility was not observed. These data suggest a pathophysiological role of ubiquinone in human seminal fluid and a molecular defect in the spermatozoa of varicocele patients.