Aim: To study the effect of experimental left varicocele (ELV) on epididymal structure and function in adolescent Sprague-Dawley rats. Methods: ELV was induced by partial ligation of the left renal vein. Sham-operated animals served as the controls. Four and 8 weeks after the operation, the histological, ultrastructural and biochemical (alpha-glucosidase activity and carnitine content) changes in different segments of the epididymis were observed. Results: In the treated animals, there were degeneration of the epididymal epithelium and edema of the interstitial tissue; numerous shedding cells, residual bodies, deformed sperm and macrophages appeared in the epididymal lumen. Morphometric measurement indicated a significant reduction in the epididymal tubular diameter (P<0.05) and a significant increase in the epididymal interstitial area (P<0.05) compared with the controls. Ultrastructural study showed sparse microvilli of the columnar epithelium, increased and enlarged lysosomes in the principal cells wi Aim: To study the effect of experimental left varicocele (ELV) on epididymal structure and function in adolescent Sprague-Dawley rats. Methods: ELV was induced by partial ligation of the left renal vein. Sham-operated animals served as the controls. Four and 8 weeks after the operation, the histological, ultrastructural and biochemical (alpha-glucosidase activity and carnitine content) changes in different segments of the epididymis were observed. Results: In the treated animals, there were degeneration of the epididymal epithelium and edema of the interstitial Morphometric measurements showed a significant reduction in the epididymal tubular diameter (P <0.05) and a significant increase in the epididymal interstitial area (P <0.05) compared to those in the epididymal lumen with the controls. Ultrastructural study showed sparse microvilli of the columnar epithelium, increased and enlarged lysosomes in the principal cells wi