放射性胸腺损伤小鼠模型的建立

背景：胸腺对于维持机体免疫功能起着重要的作用,在放射性损伤发生时的损伤和修复机制有待于进一步研究,但目前缺乏相应的动物模型。 目的：单纯照射小鼠胸腺以构建放射性胸腺损伤模型。 方法：160只雌性BALB/C小鼠随机分为4组,每组40只,对照组予以假照射;6 Gy照射组给予⁶⁰Co γ射线6 Gy胸腺单次照射,9 Gy照射组给予胸腺单次照射9 Gy,12 Gy照射组给予胸腺单次照射12 Gy。观察各组小鼠照射后1-7 d体质量及进食水量变化,照射后1,7,14,21,28 d检测各组小鼠血象、胸腺指数及胸腺病理变化,并于照射后7 d检测小鼠食管、肺、气管病理组织学变化,照射后14 d检测小鼠外周血T细胞亚群和胸腺T细胞亚群表达。 结果与结论：与对照组相比,照射组小鼠各项指标均发生变化,但6 Gy照射组由于损伤相对较轻,在照后1周内就开始修复;12 Gy照射组出现了放射性食管、气管损伤,而9 Gy组即保留了放射性损伤的特点,也避免了其他脏器损伤带来的干扰,能反映胸腺放射性损伤后的改变。以9 Gy ⁶⁰Co γ射线单次纵膈照射可成功制作小鼠放射性胸腺损伤模型。

Establishing a mouse model of radiation-induced thymus injury

BACKGROUND: The thymus plays an important role in maintaining the immune function of the body. Damage and repair mechanisms of radiation-induced thymus injury require further studies, but there lacks an appropriate animal models.     OBJECTIVE: To establish a mouse model of radiation-induced thymus injury. METHODS: Totally 160 female BALB/C mice were randomly classified into four groups, 40 mice in each group: control group received sham-irradiation, and the other groups were irradiated with different doses of ⁶⁰Co γ-rays, 6 Gy, 9 Gy and 12 Gy. After the irradiation, the body mass, food and water intake, the thymus index, and thymus pathology were detected at 1, 7, 14, 21, 28 days; esophageal, trachea and lung pathological changes were observed at 7 days; thymus and peripheral blood T subsets of the mice were measured at 14 days. RESULTS AND CONCLUSION: ALL three doses (6 Gy, 9 Gy, 12 Gy) could damage mouse thymus. After 6 Gy radiation, radiation-induced thymus injury was relatively mild and repaired within 1 week. Radioactive esophagus and trachea injury were found in mice exposed to 12 Gy radiation. Only exposed to 9 Gy, the thymus had a typical change and other organs were normal. Therefore, single mediastinal ⁶⁰Co γ-ray irradiation at a dose of 9 Gy can successfully produce a mouse model of radioactive thymus injury.