Haeri S A, Rajabi H, Fazelipour S, Hosseinimehr S J
Faculty of Medical Sciences, Department of Medical Physics, Tarbiat Modares University, Tehran, Iran.
Andrologia. 2014;46(9):1041-6. doi: 10.1111/and.12193. Epub 2013 Nov 12.
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.
本研究调查了天然存在的二肽肌肽对睾丸损伤的辐射防护作用。在γ射线照射（2 Gy）前4天，通过腹腔注射将肌肽（10、50和100 mg kg⁻¹体重）给予雄性小鼠。在照射后12小时和14天，采用TUNEL法评估细胞凋亡情况，并评估组织病理学参数。与单纯辐射组不同，照射前用肌肽预处理可显著降低所有剂量辐射处理诱导的TUNEL阳性细胞频率，肌肽剂量为10、50和100 mg kg⁻¹体重时，降低因子分别为1.8、2.47和2.23。暴露于电离辐射会减少精子数量，并降低生精上皮小管的高度和直径。与仅接受辐射处理的组相比，所有剂量的肌肽预处理均显著增加了生精上皮高度和小管直径，也增加了生殖细胞数量。这些结果表明，肌肽通过抗凋亡作用预防γ射线照射诱导的睾丸功能障碍；睾丸功能的这种恢复最终导致精子发生的恢复。
