Experimental varicocele induces testicular germ cell apoptosis in the rat

Purpose: We evaluated the impact of experimentally created varicocele on ipsilateral and contralateral testicular germ cells in the rat. Materials and Methods: Experimental left varicocele was created by partial ligation of the left renal vein in 17 adult male Sprague-Dawley rats. An additional 5 rats that underwent laparotomy and renal vein handling without ligation served as sham surgical controls. Five rats that underwent no surgical or other intervention served as a control group. Rats were sacrificed 7 (5), 14 (5) or 28 (7) days following varicocele creation. Germ cell apoptosis was quantified using a TUNEL assay. The results of this assay are expressed as the number of apoptotic germ cell nuclei per seminiferous tubular cross section. The presence of apoptosis was confirmed by cellular ultrastucture evaluation using transmission electron microscopy. Results: Control and sham animals were found to have a mean of 0.05 and 0.15 apoptotic germ cells per seminiferous tubular cross section, respectively. Rats sacrificed 7, 14 and 28 days after varicocele creation were found to have 0.15, 0.23 and 0.27 apoptotic germ cells per tubule in the ipsilateral testis, and 0.14, 0.16 and 0.17 apoptotic germ cells per tubule in the contralateral testis, respectively. Compared with control animals a statistically significant increase in the number of apoptotic germ cells per tubular cross section was noted 14 days following varicocele creation in the ipsilateral testis (p <0.05). Conclusions: The creation of experimental varicocele generated an increase in germ cell apoptosis in the ipsilateral testis at 14 days compared with control animals.