Protective Effects of Topical Application of Nitrite on Testicular Ischemia-Reperfusion Injury in Rats

Testicular torsion is a urologic emergency induced by torsion of the spermatic cord, interrupting blood circulation to the testis. Therapeutic options for testicular torsion, except surgical restoration of testis, are rarely applied in clinical practice. This study, therefore, investigated whether topical application of nitrite (NO2-) is beneficial in tissue damage due to testicular ischemia-reperfusion (I/R) injury in rats. Pubertal Sprague-Dawley rats were assigned to seven groups: group A, sham-operated control group; group B, I/R with no treatment; groups C, D, and E, I/R followed by treatment with three different doses of nitrite; group F, I/R followed by administration of nitrite and a NO scavenger, C-PTIO (2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt); and group G, I/R followed by administration of nitrate (NO3-). Unilateral testicular ischemia was maintained for 5 h, followed by reperfusion for 24 h. Nitrite and nitrate were topically administered before reperfusion. Compared to group A, germ cell apoptosis, oxidative stress, antioxidant enzymatic function, and lipid peroxidation were significantly increased, along with abnormal morphology and impaired spermatogenesis in group B (P<0.05). In contrast, testicular damage was generally attenuated in the nitrite treatment groups due to a reduction in superoxide and peroxynitrite levels and the inhibition of caspase-3-dependent apoptosis (P