The protective effect of L-arginine, tadalafil, and their combination in rat testes after ischemia and reperfusion injury

Abstract

Introduction: Nitric oxide (NO) plays an important role in the ischemia and reperfusion process. In this study, we aimed to examine the effect of L-arginine, tadalafil, and their combination for prevention of the ischemia reperfusion injury after testis torsion in rats.

Methods: A total of 40 adult, male Sprague-Dawley rats were allocated into five groups. Three hours of left testicular torsion was performed in each group, excluding the control group. While the ischemia reperfusion (I/R) group had no treatment, I/R + Arg group received L-arginine, I/R + Td group received tadalafil and I/R + Arg + Td group received tadalafil and L-arginine 30 minutes before the detorsion. Then the left testis was untwisted for four hours of reperfusion. After bilateral orchiectomy, lipid peroxidation (LPx) and glutathione (GSH) activities were examined in testicular tissue. Spermatogenesis was evaluated with Johnsen's score.

Results: LPx levels of the I/R group were found to be significantly higher than for groups that received drugs for both testes (p<0.001). GSH levels of the combination group were higher than I/R group in ipsilateral testis (p<0.01) and it was significantly higher than other groups for contralateral testis (p<0.001 for I/R group, p<0.01 for I/R + Arg, p<0.05 for I/R + Td). Mean Johnsen's score of the I/R group was found to be significantly lower than treatment groups in ipsilateral testis (p<0.001 for I/R + Arg + Td group, p<0.01 for other treatment goups) and contralateral testis (p<0.001). The mean Johnsen score of the combination group was significantly higher than that of other treatment groups in ipsilateral testis (p<0.05) and it was significantly higher than in the I/R + Td group in the contralateral testis (p<0.05).

Conclusions: L-arginine, tadalafil, and combination of these two molecules showed protective effect against ischemia/reperfusion injury for both testes after unilateral testis torsion.

Fig. 1.

(A) Comparison of Lpx levels in ipsilateral testis; p<0.05 Mann-Whitney U test, bar represent mean ± standard deviation (SD) values; (B) comparison of Lpx levels in contralateral testis; p<0.05 Mann-Whitney U test, bar represent mean ± SD values. ^***p<0.001; ^**p<0.01; ^*p<0.05. Arg: L-arginine; I/R: ischemia/reperfusion; Lpx: lipid peroxidation; Tdf: tadalafil.

Fig. 2.

(A) Comparison of GSH levels in ipsilateral testis p<0.05 Mann-Whitney U test; bar represent mean ± standard deviation (SD) values; (B) comparison of GSH levels in contralateral testis; p<0.05 Mann-Whitney U test, bar represent mean ± SD values. ^***p<0.001; ^**p<0.01; ^*p<0.05. Arg: L-arginine; GSH: glutathione; I/R: ischemia/reperfusion; Tdf: tadalafil.

Fig. 3.

(A) Normal morphological appearance of seminiferous tubule; spermatids are present in ipsilateral testis of control group (black arrow); (B) maturation arrest of germ cells, desquamation and disorganization of germ cell layer in ipsilateral testis of ischemia/reperfusion (I/R) group (black arrow); (C) maturation arrest, desquamation, and disorganization of germ cell layer in contralateral testis of I/R group; (D) degeneration and maturation arrest in germinal cells was noticed in ipsilateral testis of I/R + L-arginine group and spermatocytes were preserved (black arrow). Hemorrhage and edema around the vessels were noticed (white arrow); (E) degeneration and maturation arrest in germinal cells was noticed in ipsilateral testis of I/R + tadalafil group and spermatocytes were preserved (black arrow). Hemorrhage and edema around the vessels were noticed (white arrow); (F) in combination group hemorrhage and edema was not evident in ipsilateral testis. A better level of maturation of spermatids were recognized than in other treatment groups (black arrow).

Fig. 4.

(A) Comparison of mean Johnsen’s scores in ipsilateral testis; p<0.05 Mann-Whitney U test, bar represent mean ± standard deviation (SD) values; (B) comparison of mean Johnsen’s scores in contralateral testis; p<0.05 Mann-Whitney U test, bar represent mean ± SD values. ^***p<0.001; ^**p<0.01; ^*p<0.05. Arg: arginin; I/R: ischemia/reperfusion; Tdf: tadalafil.