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 < 0.05 vs. group B). These
therapeutic effects of
nitrite-derived NO were suppressed after injection of C-
PTIO, which showed in group F. Taken together, our results demonstrate that topical application of
nitrite may be one of the therapeutic strategies for testicular
ischemia-reperfusion injury.