Carnosine mitigates apoptosis and protects testicular seminiferous tubules from gamma-radiation-induced injury in mice.

This study investigated the radioprotective effects of a naturally occurring dipeptide, carnosine, on testicular damage. Carnosine was administered (10, 50 and 100 mg kg(-1) body weight) to male mice via intraperitoneal injection for 4 days prior to gamma irradiation (2 Gy). Apoptosis with the TUNEL assay and histopathological parameters were evaluated 12-h and 14-day post-irradiation. Pre-treatment with carnosine before irradiation significantly reduced the frequency of TUNEL-positive cells induced by radiation treatment at all doses by reduction factors of 1.8, 2.47 and 2.23 for carnosine at 10, 50 and 100 mg kg(-1) bw, respectively, unlike that observed in the radiation alone group. Exposure to ionising radiation decreased sperm count and reduced the height and diameter of seminiferous epithelial tubules. Pre-treatment with all doses of carnosine significantly augmented seminiferous epithelial height and tubule diameter and also increased the number of germinal cells in comparison to the group treated with radiation only. These results indicate that carnosine prevents testicular dysfunction induced by gamma-irradiation via an anti-apoptotic effect; this restoration of proper testicular function ultimately leads to the recovery of spermatogenesis.