Oxidative Stress and Cell Cycle Arrest in Seminiferous Tubules Nearby Varicose Vessels: New Perspectives from Experimental Varicocele.

Abstract

Varicocele (VCL) has been shown to induce severe oxidative stress in the testicular tissue resulting in 35% of males with primary infertility. To compare the exacerbating impacts of varicose on oxidative DNA damage and homeostatic antioxidant reactions in the seminiferous tubules (ST), enclosed and far from varicose vessels. Thirty mature Wistar rats were divided into control and VCL-induced groups. To approve VCL, the testicular diameters, volume, and blood circulation were measured using B-mode and Doppler ultrasonography. Next, to confirm oxidative stress (OS), the global homeostatic antioxidant biomarkers were evaluated. Moreover, the OS-induced oxidative DNA damage and homeostatic antioxidant reactions were compared between STs nearby and far from varicose vessels. Finally, to clarify the DNA damage-induced impact on the cell cycle progression, the global and local expressions of Cyclin D1, Cdk4, and p21 were examined. The VCL-induced group exhibited diminished global antioxidant status (marked with TAC, GPX, SOD, and CAT) and UNG and MPG expression levels. Moreover, the cross-sections of the VCL group represented a prominent reduction in the UNG, MPG, Cyclin D1, and cdk4, and upregulation in the p21 expression levels, more prominently in the STs nearby varicose vessels. Concerning severe oxidative DNA damage and intensive molecular changes in the STs nearby the varicose vessels, they can be considered the main cause of oxidative DNA damage in enclosed tubules. Thus, the varicose-mediated oxidative DNA damage negatively impacts the cell cycle progression in the tubules more intensively in the subcapsular area.