Seminal quality correlates with mitochondrial functionality

Oligozoospermia is an important manifestation of male subfertility and very little attention has been paid to study a possible relationship between th e total number of ejaculated spermatozoa and mitochondrial functionality. I n this work we report a direct correlation between spectrophotometrically m easured mitochondrial enzyme activities (citrate synthase and respiratory c omplex I, II, I + III, II + III and IV) and seminogram parameters (sperm mo tility, vitality and cell concentration). In addition, total ejaculated spe rmatozoa correlate much better with the nuclear-encoded citrate synthase an d complex II than with the mitochondrial-encoded complex I, III and IV acti vities. Furthermore, total number of spermatozoa has a significant but nega tive correlation with the ratios of complex I, complex III and complex IV t o complex II (and citrate synthase). These ratios are significantly higher in aged subjects emphasizing the physiological relevance of this observatio n. These results suggest that the simultaneous increase of the number of ej aculated spermatozoa and the mitochondrial enrichment of citrate synthase a nd complex II are both parallel responses to the same regulatory events. (C ) 2000 Elsevier Science B.V. All rights reserved.