Objective: To study the impact of left varicocele (VC) and varicocelectomy (VCT) on the apoptosis of spermatogenic cells and the levels of nitrogen monoxidum (NO) and interleukin 1 (IL-1) in the rat testis.
Methods: We randomly divided 60 adolescent male SD rats into four groups of equal number: sham operation control, VC model 1 (VC1), VC model 2 (VC2), and VCT. We determined the semen quality and levels of NO and IL-1 in the testis tissue, detected the apoptosis of spermatogenic cells by TUNEL, and compared the indexes obtained among different groups.
Results: An experimental VC model was successfully established by partially ligating the left renal vein of the rats. Sperm concentration and motility were significantly decreased in the VC1 ([1.54 ± 1.16] x 10⁶/ml and [44.23 ± 15.46]%) as compared with those in the sham operation group ([2.80 ± 1.62] x 10⁶/ml and [72.34 ± 12.62]%) (P < 0.05), but remarkably higher in the VCT ([1.82 ± 1.34] x 10⁶/mI and [51.21 ± 12.62]%) than in the VC2 group ([1.04 ± 1.21] x 10⁶/ml and [39.23 ± 13.21]%) (P < 0.05). The levels of NO and IL-1 in the left testes were markedly elevated in the VC1 ([0.172 ± 0.030] ng/ml and [1.468 ± 0.080 ] mg/ml) in comparison with those in the sham operation group ([0.134 ± 0.021] ng/ml and [0.782 ± 0.079 ] mg/ml) (P < 0.05), and significantly higher in the VC2 ([0.198 ± 0.020] ng/ml and [1.994 ± 0.090] mg/ml) than in the VCT group ([0.141 ± 0.010] ng/ml and [0.781 ± 0.036] mg/ml) (P < 0.05). However, the NO and IL-1 levels in the right testis showed no statistically significant differences between the two groups, and the two levels were positively correlated (r = 0.492, P < 0.01). The rats of the VC1 group exhibited remarkable apoptosis of spermatogenic cells in the bilateral testes, with significant differences in the apoptosis index ( AL) between the two sides (P < 0.05) as well as in the same side in comparison with the sham operation group (P < 0.01). The Als of spermatogenic cells in the bilateral testes showed statistically significant differences in the VCT (P < 0.05) but not in the VC2 group (P > 0.05), and those in the same side manifested dramatic differences between the VCT and VC2 groups (P < 0.01).
Conclusion: Varicocele induces changes of the NO and IL-1 levels in the testis tissue and increases the apoptosis of spermatogenic cells, which might be one of the causes of testis damage and spermatogenic dysfunction.