Abstract: To obtain the information of the normal parameters of physiology and biochemistry, tumor sensitivity and resisance to ionizing radiation, and determine indication of hematology and serum biochemistry, G_banding pattern, spontaneous aberration frequency, LD\-\{50\} to 137 Cs γ ray and changes of mucleated cell count, DNA content, CFU_S in bone marrow cells and WBC in peripheral blood following irradiated with 4 Gy 137 Cs γ ray were performed in IRM_2 mouse. The results showed that chromosome break rate wad 0\^33%, and centric aberration and traslocation rate was 0\^08%, respectively. LD\-\{50\} to 137 Cs γ ray were 7\^17(♂)～7 50(♀), that is 1.73～1.57 Gy and 1.44 Gy higher than those of ICR and 615 mouse, respectively. The sensitivity to T_739 lung adenocarcinoma and breast cancer was higher. IRM_2 inbred strain mouse had the following properties:the stabile parameters of hematology and serum biochemistry, low spontaneous aberration frequency and higher resistance to ionizing radiation.

Key words: IRM-2 mouse, Biological character, Radiation resistance, Tumour

摘要： 目的　对IRM_2近交系小鼠的生物学特性、血液生理指标、G_显带核型及自发畸变率、γ射线半数致死剂量(LD50 )、造血功能三项指标的测定和肿瘤易感性进行了研究。方法　采用自动光电血球计数仪计数、小鼠骨髓制备和G显带法 ,对1 37Csγ射线的LD50 测定及小鼠经 4 0Gy1 37Csγ射线照射后不同时期骨髓的有核细胞总数、脾指数、脾结节的变化 ;采用肿瘤的瘤块及悬液接种。结果　IRM_2小鼠血液生理指标稳定 ,个体间差异较小 ;G显带核型结构畸变分析 ,断裂占 0 33% ;无着丝粒畸变和不平衡易位均为 0 0 8% ,自发畸变率低。LD50 雄性为 7 17Gy,雌性为7 5Gy ,与ICR和 6 15小鼠比较 ,有非常显著的差异 ,对电离辐射具有更强的耐受性。造血功能三项指标均显著高于ICR和 6 15小鼠 ,CFU_S数比ICR和 6 15小鼠分别高出一倍和三倍。接种恶性淋巴瘤连续传 15 2代、移植乳腺癌瘤株75代、肺腺癌瘤株 5代 ,成瘤率均为 10 0 %。自发性恶性淋巴瘤具有较强的特异性

关键词: IRM-2小鼠, 生物学特性, 辐射抗性, 肿瘤