Male factor infertility has increased to more than 40% during the last decade. About 30% of these couples are diagnosed with unexplained infertility. In fact, reactive oxygen species (ROS), especially superoxide anion (O2 −·) and hydrogen peroxide (H2O2), play a crucial role in regulation of physiological and pathological processes in spermatozoa. Moreover, since the diagnosis of unexplained infertility just through semen analysis is a matter of much controversy; we aimed to evaluate the levels of ROS and sperm DNA fragmentation in the semen samples of unexplained infertile and fertile control couples.
The semen samples of 28 unexplained infertile couples and 30 fertile control couples were analyzed according to WHO criteria. The intracellular levels of H2O2 and O2 −· were detected by flow cytometry with 2′,7′-Dichlorodihydrofluorescin diacetate and Dihydroethidium, respectively, and DNA fragmentation was evaluated by sperm chromatin dispersion test.
In unexplained infertile group, sperm motility and normal morphology were significantly lower than the control. The levels of sperm H2O2, O2 −·, and DNA fragmentation were significantly higher in unexplained infertile men compared to fertile. Moreover, a positive correlation was found between the level of H2O2 and sperm DNA fragmentation in the unexplained infertile group. Besides, reduced sperm motility in the unexplained infertile group was significantly correlated with elevated levels of ROS.
The higher levels of intracellular ROS and DNA fragmentation in the semen samples of unexplained infertile couples and their causes might be considered as an important factor related to diagnosis and treatment of the unexplained infertile couples.
Zahra Zandieh, Akram Vatannejad, Mahmood Doosti, Sara Zabihzadeh, Mahnaz Haddadi, Leila Bajelan, Batool Rashidi, Saeid Amanpour
Department of Anatomical Sciences, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
Department of Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
Valie-Asr Reproductive Health Research Centre, Tehran University of Medical Sciences, Tehran, Iran
Cancer Biology Research Center, Tehran University of Medical Sciences, Tehran, Iran
Mehr IVF Centre, Mehr Hospital, Tehran, Iran
Irish Journal of Medical Science, 2017, pp. 1-6.