Abstract
Varicocele, defined by a dilation of efferent testicular veins, is the most commonly identifiable, surgically correctable lesion associated with male-factor infertility, starts at puberty and causes a progressive decline in fertility potential. The pathophysiology of infertility caused by this disease is still poorly understood, but it is suggested that the main mechanism is oxidative stress. Therefore, the aim of this study was to verify if the varicocele is associated with changes in enzymatic antioxidant mechanisms and seminal plasma lipid peroxidation levels in adolescents. We recruited 90 adolescents that were divided into control (C; n = 27); varicocele and normal semen (VNS; n =46); varicocele and altered semen (VAS; n =17). Seminal and serum levels of lipid peroxidation were quantified by thiobarbituric acid reactive substances (TBARS). Seminal plasma antioxidant profile was evaluated by the activities of catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD). The VAS group had increased lipid peroxidation levels when compared to the other groups. The levels of serum lipid peroxidation and activities of the enzymes SOD and GPx did not differ between groups. CAT was undetectable by the method used. In conclusion, in adolescents with varicocele and altered semen analysis, there is an increase in seminal lipid peroxidation levels compared to adolescents with varicocele and without seminal change and adolescents without evident varicocele. However, the observed oxidative stress is not caused by a decrease in superoxide dismutase and glutathione peroxidase activities, which did not differ between adolescents with and without evident varicocele. Lay summary: Varicocele, defined by a dilation of efferent testicular veins, is the most commonly identifiable, surgically correctable lesion associated with male-factor infertility, starts at puberty and causes a progressive decline in fertile potential. There is still much that is not understood regarding how exactly it affects semen quality, but most studies agree that oxidative stress, which is defined as excessive amounts of free radicals in relation to antioxidant defense, is an important mechanism. In this study, we aimed to verify if the varicocele is associated with changes in antioxidant defense and semen oxidation in 90 adolescents with and without varicocele. In adolescents with varicocele and abnormal semen, there is an increase in semen oxidation compared to controls or to the group with varicocele and normal semen quality. Our results can help to understand how varicocele leads to infertility in adolescents, identifying changes in oxidative activity in semen, since the onset of varicocele and before damage to sperm production can be detected.