Short and long‐term effects of experimental varicocele.

Background: Varicocele is associated with a progressive decrease in male fertile potential, but it has yet to be determined if the duration of varicocele is associated with altered sperm functional quality. Objectives: This experimental study investigated the time‐dependent effects of varicocele on spermatogenesis, sperm parameters, and sperm functional traits. Materials and methods: Thirty‐five mature male Wistar rats (200 ± 25 g) were included. After 2 weeks of adaptation, rats were randomly divided (n = 7/group) into control, 2 months sham (sham‐2), 2 months varicocele (VCL‐2), 4 months sham (sham‐4), and 4 months varicocele (VCL‐4) groups. Cauda epididymides were incised transversally and incubated in Biggers–Whitten–Whittingham media at 37°C for 30 min. Sperm concentration, motility, morphology, viability, mitochondrial activity (3,3′ diaminobenzidine staining), acrosome integrity (PNA‐FITC), and DNA fragmentation (alkaline Comet assay) were determined. Histological analysis on testicular cross‐sections was performed using H&E staining, and Johnsen's score was determined for each sample. Results: Decreased Johnsen score, sperm count, motility, viability, normal morphology, and mitochondrial activity were observed in VCL‐2 and VCL‐4 groups when compared with sham‐2, sham‐4, and control groups. Higher levels of acrosome damage and DNA fragmentation were observed in VCL‐2 and VCL‐4 groups compared to sham and control groups. A negative correlation was observed between Johnsen scores and acrosome damage (r = –0.7690; p < 0.0001), and a positive correlation was observed between Johnsen scores and sperm DNA fragmentation (r = 0.8333; p < 0.0001). No differences were observed between the VCL‐2 and VCL‐4 groups in any of the analyses. Discussion and conclusion: Experimental varicocele leads to decreased semen quality, sperm functional integrity, and Johnsen's scores. Moreover, to our knowledge, this is the first study demonstrating a direct association between spermatogenesis and sperm count, motility, acrosomal integrity, and DNA fragmentation levels in experimental varicocele. Longer periods of varicocele did not potentiate the negative effects, in this study. [ABSTRACT FROM AUTHOR]