Rivera E S, Andrade N, Martin G, Melito G, Cricco G, Mohamad N, Davio C, Caro R, Bergoc R M
Laboratorio de Radioisótopos, Cátedra de Fisica, Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires, Argentina.
Cancer Lett. 1994 Nov 11;86(2):223-8. doi: 10.1016/0304-3835(94)90082-5.
In order to obtain an experimental model we induced mammary tumors in female Sprague-Dawley rats. The carcinogen N-nitroso-N-methylurea (NMU) was injected intraperitoneally (i.p.) at doses of 50 mg/kg body weight when animals were 50, 80 and 110 days old. Tumor sizes were measured with a caliper and their growth parameters and histopathological properties were tested. For 100 rats, 88.4% of developed lesions were ductal carcinomas, histologically classified as 52.8% cribiform variety, 30.6% solid carcinoma. Metastases in liver, spleen and lung were present. Other primary tumors were detected with low incidence. The influence of the rat estrous cycle during the first exposure to intraperitoneal NMU injection was studied. The latency period in estrus, proestrus and diestrus was 82 +/- 15, 77 +/- 18 and 79 +/- 18 days, respectively. Tumor incidence was significantly higher in estrus (95.2%) than proestrus (71.4%) or diestrus (77.4), (P < 0.01). Mean number or tumors per animal was similar among the three groups (4.4 +/- 3.2, 3.8 +/- 3.6, 3.2 +/- 1.8). The procedure described appears to be the simplest method for inducing experimental mammary tumors in rats.
为了获得实验模型，我们在雌性斯普拉格-道利大鼠中诱发乳腺肿瘤。当动物50、80和110日龄时，腹腔注射致癌剂N-亚硝基-N-甲基脲（NMU），剂量为50mg/kg体重。用卡尺测量肿瘤大小，并测试其生长参数和组织病理学特性。在100只大鼠中，88.4%的病变为导管癌，组织学分类为52.8%筛状型、30.6%实体癌。存在肝、脾和肺转移。其他原发性肿瘤的发生率较低。研究了首次腹腔注射NMU时大鼠发情周期的影响。发情期、发情前期和间情期的潜伏期分别为82±15、77±18和79±18天。发情期的肿瘤发生率（95.2%）显著高于发情前期（71.4%）或间情期（77.4%），（P<0.01）。三组动物每只动物的平均肿瘤数相似（4.4±3.2、3.8±3.6、3.2±1.8）。所述方法似乎是在大鼠中诱发实验性乳腺肿瘤的最简单方法。
