Differential contribution of leucocytes and spermatozoa to the generation of reactive oxygen species in the ejaculates of oligozoospermic patients and fertile donors

Abstract

Summary. Cells isolated from the ejaculates of a high proportion of patients exhibiting oligozoospermia are characterized by generation rates of reactive oxygen species that considerably exceed those obtained for the normal fertile population. The purpose of this study was to resolve the cellular source of this enhanced activity. Semen samples from a cohort of oligozoospermic patients and a group of fertile controls were fractionated on discontinuous Percoll gradients to generate three cell populations (0, 50 and 100%) of differing density. For each fraction, both the steady-state and the phorbolester-induced chemiluminescent signals were significantly (P < 0\m=.\001)greater for the oligozoospermic samples than for the fertile controls. In the fertile donors, leucocytes comprised the major source of reactive oxygen species, particularly in the low-density Percoll fractions; in oligozoospermic patients, however, spermatozoa were identified as a second major source of reactive oxygen species. Particularly striking was an intense phorbol-ester-induced chemiluminescent signal generated by oligozoospermic spermatozoa, purified by passage through isotonic Percoll and free of leucocyte contamination, which was 167 times greater than the median signal generated by the corresponding fraction from the fertile controls (P < 0\m=.\001). These results emphasize the importance of spermatozoa as a major source of reactive oxygen species in oligozoospermia and have implications for the diagnosis and treatment of this condition, as well as for the design of appropriate diagnostic strategies.

Effects of aging on the male reproductive system

“…Low and medium concentrations of ROS are involved in cellular defense against infection agents, signal transduction, and response against mitogens, carboxylation, peroxidation, Pasqualotto et al [28] 0.03 ml [33] and reduction of ribonucleotides; however, high levels of ROS lead to various cellular damage [54][55][56][57][58][59]. ROS induced DNA damage involves base modifications, abasic sites, single strand (ss) and double strand (ds) DNA breaks, and DNA protein cross-links [60][61][62].…”

Sperm preparation before freezing improves sperm motility and reduces apoptosis in post-freezing-thawing sperm compared with post-thawing sperm preparation

“…Although semen analysis indicated normal results, a number of abnormal spermatozoa or leukocytes could be identified in the sample. Those cells generated reactive oxygen species (ROS), which can penetrate through the sperm plasma membrane and initiate intrinsic ROS formation inside the spermatozoa, causing sperm damage, e.g., DNA fragmentation [12,[14][15][16][17][18][19]. After cryopreservation of spermatozoa, the percentage of abnormal spermatozoa in regards to motility, morphology, and DNA integrity significantly increases after freezing-thawing process [2,19,20].…”

The Levels of Oxidative Stress Biomarkers in Rats as a Response to Different Techniques of Testicular Biopsy

“…In semen of fertile men, the amount of ROS is controlled by seminal antioxidants. The main sources of overproduction of ROS in the semen are leucocytes and morphologically abnormal spermatozoa [28]. Some authors demonstrated that high levels of ROS were detected in the semen of 25 to 40 % of infertile men [29].…”