Nagler R M, Reznick A Z, Slavin S, Nagler A
Department of Anatomy and Cell Biology, Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
Arch Oral Biol. 2000 Sep;45(9):741-7. doi: 10.1016/s0003-9969(00)00046-7.
Head-and-neck irradiation in rats often results in reduction of water and food intake, weight loss, hyposalivation, and suppression of the white blood cell (WBC) count. Oxygen free radicals are believed to be involved in this deleterious process. Superoxide dismutase (SOD) is known to act as a first line of antioxidant defence against oxygen free radicals. Here, the protective effect of manganese SOD (MnSOD) and copper/zinc SOD (Cu/ZnSOD) against irradiation-induced injuries to the head and neck in rats was investigated. Wistar rats were irradiated with 15 Gy X-rays delivered to the head-and-neck region. MnSOD (50 mg/kg) or Cu/ZnSOD (100 mg/kg) were administered before and after irradiation. Body weight, food and water intake, WBC counts, and parotid and submandibular salivary functions were examined. Irradiation of 15 Gy resulted in a significant reduction of the parotid flow rate by 73% compared with non-irradiated controls (p<0.05). MnSOD but not Cu/ZnSOD partially reduced this effect on the parotid gland by 25% (p<0.05). Both MnSOD and Cu/ZnSOD demonstrated a protective effect against irradiation-induced WBC suppression, by 35% and 25%, respectively (p<0.05). Treatment with SOD did not protect the animals against irradiation-induced reduction in oral intake and weight loss, or against submandibular hypofunction. These results suggest that SOD partially protects against head-and-neck irradiation-induced injury. Both MnSOD and Cu/ZnSOD partially protect against irradiation-induced WBC loss. The parotid gland is partially protected by MnSOD but not Cu/ZnSOD, while the submandibular gland is not protected by either MnSOD or Cu/ZnSOD.
对大鼠进行头颈部照射通常会导致水和食物摄入量减少、体重减轻、唾液分泌减少以及白细胞（WBC）计数受到抑制。氧自由基被认为参与了这一有害过程。超氧化物歧化酶（SOD）作为对抗氧自由基的第一道抗氧化防线而发挥作用。在此，研究了锰超氧化物歧化酶（MnSOD）和铜/锌超氧化物歧化酶（Cu/ZnSOD）对大鼠头颈部辐射损伤的保护作用。将15 Gy的X射线照射到Wistar大鼠的头颈部区域。在照射前后分别给予MnSOD（50 mg/kg）或Cu/ZnSOD（100 mg/kg）。检测体重、食物和水摄入量、白细胞计数以及腮腺和颌下腺的唾液功能。与未照射的对照组相比，15 Gy的照射导致腮腺流速显著降低73%（p<0.05）。MnSOD而非Cu/ZnSOD使腮腺的这种效应部分降低了25%（p<0.05）。MnSOD和Cu/ZnSOD均对辐射诱导的白细胞抑制表现出保护作用，分别为35%和25%（p<0.05）。用SOD治疗并不能保护动物免受辐射诱导的口腔摄入量减少和体重减轻，也不能防止颌下腺功能减退。这些结果表明，SOD可部分预防头颈部辐射诱导的损伤。MnSOD和Cu/ZnSOD均部分预防辐射诱导的白细胞损失。腮腺受到MnSOD的部分保护，但未受Cu/ZnSOD的保护，而颌下腺既未受到MnSOD的保护，也未受到Cu/ZnSOD的保护。
