Seminal plasma reactive oxygen species-antioxidants relationship with varicocele grade

The hypoxic testicle: physiology and pathophysiology

Mammalian spermatogenesis is a complex biological process occurring in the seminiferous tubules in the testis. This process represents a delicate balance between cell proliferation, differentiation, and apoptosis. In most mammals, the testicles are kept in the scrotum 2 to 7°C below body core temperature, and the spermatogenic process proceeds with a blood and oxygen supply that is fairly independent of changes in other vascular beds in the body. Despite this apparently well-controlled local environment, pathologies such as varicocele or testicular torsion and environmental exposure to low oxygen (hypoxia) can result in changes in blood flow, nutrients, and oxygen supply along with an increased local temperature that may induce adverse effects on Leydig cell function and spermatogenesis. These conditions may lead to male subfertility or infertility. Our literature analyses and our own results suggest that conditions such as germ cell apoptosis and DNA damage are common features in hypoxia and varicocele and testicular torsion. Furthermore, oxidative damage seems to be present in these conditions during the initiation stages of germ cell damage and apoptosis. Other mechanisms like membrane-bound metalloproteinases and phospholipase A2 activation could also be part of the pathophysiological consequences of testicular hypoxia.

The hemodynamic approach to evaluating adolescent varicocele

During adolescence, the risk of developing a varicocele increases. Prevalence is less than 1% in boys aged younger than 10 years, but approaches that of the general adult population (about 15%) during puberty. For adolescent males with varicoceles, surgical risk factors have not yet been clearly delineated and clinical severity correlates poorly with prognosis. Fortunately, the widespread use of Doppler ultrasonography is transforming the diagnostic work-up for this demographic. A continuous reflux detected by color Doppler ultrasound (CDUS) is thought to have a negative prognostic value and evidence suggests that a peak retrograde flow above 38 cm per second is a powerful predictor of lack of spontaneous improvement in adolescent patients with ≥ 20% asymmetry between testes. CDUS also enables the detection of varicocele resulting from reflux in the deferential vein adjunctive to a refluxing internal spermatic vein; a causality that accounts for approximately 15% of cases. In addition to a diagnostic role, hemodynamic parameters can be used to predict the risk of persistence or worsening asymmetry. Although further studies are necessary to validate single parameters, it seems that the more severe the reflux, the greater the likelihood that the patient will develop testicular asymmetry.

Grade 3 varicocele in fertile men: a different entity

PURPOSE

Although varicocele size has an inverse relationship with baseline semen parameters and a direct relationship with seminal reactive oxygen species in infertile patients, to our knowledge the effect of varicocele grade in fertile men is unknown. We evaluated the impact of varicocele grade on seminal parameters, testicular size and seminal reactive oxygen species in fertile men.

MATERIALS AND METHODS

We prospectively evaluated 194 men from July 2004 to April 2010. Of the men 156 were fertile and classified by presence of varicocele. A total of 38 infertile patients with varicocele as the only identifiable cause of infertility comprised the control group. Physical examination, semen parameters and seminal reactive oxygen species were compared between the groups.

RESULTS

Of 156 fertile men 43 (24.3%) had clinical varicocele, which was grade 1 to 3 in 22, 11 and 10, respectively. The remaining 113 men (72.7%) had no varicocele. Infertile men had smaller testes, decreased semen parameters and higher seminal reactive oxygen species than the fertile groups. Testicular size, reactive oxygen species and semen parameters did not differ between fertile men with vs without varicocele. Fertile men with varicocele grade 3 had higher seminal reactive oxygen species than those with lower grade varicocele. As varicocele grade increased, seminal reactive oxygen species increased and sperm concentration decreased.

CONCLUSIONS

Although fertile men have more efficient defense mechanisms to protect against the consequences of varicocele on testicular function, these mechanisms may not be sufficient in those with varicocele grade 3. Further research is needed to clarify whether they are at increased risk for future infertility.