Tsubura A, Izuno Y, Shoji T, Kusunose N, Morii S
Department of Pathology, Kansai Medical University, Moriguchi, Japan.
Acta Pathol Jpn. 1990 Jan;40(1):9-13. doi: 10.1111/j.1440-1827.1990.tb01523.x.
In order to determine the influence of strain and sex on local carcinogenesis in rat mammary tissue, 1 mg of 7,12-dimethylbenz(a)anthracene (DMBA) was dusted directly onto the exposed mammary gland of 30-day-old Long-Evans (L-E) rats and Sprague-Dawley (S-D) rats. The experiment was terminated 28 weeks after application of the carcinogen. Tumors measuring between 1 and 2 cm in diameter were harvested from female L-E rats with high frequency (85%) and long latency (mean: 23.7 weeks after DMBA dusting), and from female S-D rats with extremely high frequency (98%) and short latency (16.7 weeks). Male rats of both strains were almost identically much less susceptible to DMBA (L-E; 55%, 25.0 weeks, S-D; 53%, 23.9 weeks). Ovariectomized S-D (47%, 24.9 weeks) and orchiectomized S-D (30%, 24.8 weeks) rats, which were gonadectomized at 30 days of age, respectively, were also much less susceptible. A variety of histologies, mostly malignant epithelial, mesenchymal or mixed tumors, were noted in each group. The carcinomatous response in the mammary tissue was much higher in female S-D (96%) than in female L-E (50%) rats, and very low in male and gonadectomized rats (10-20%). In contrast, the sarcomatous response in the mammary tissue was moderate in female and male L-E and male S-D (43-50%) rats, and low in the other groups (15-29%).
为了确定品系和性别对大鼠乳腺组织局部致癌作用的影响，将1毫克7,12 - 二甲基苯并(a)蒽（DMBA）直接涂抹于30日龄的长 Evans（L - E）大鼠和斯普拉格 - 道利（S - D）大鼠暴露的乳腺上。在涂抹致癌物28周后终止实验。从雌性L - E大鼠中高频（85%）且潜伏期长（平均：DMBA涂抹后23.7周）收获直径在1至2厘米之间的肿瘤，从雌性S - D大鼠中以极高频率（98%）且潜伏期短（16.7周）收获。两种品系的雄性大鼠对DMBA的易感性几乎相同且低得多（L - E；55%，25.0周，S - D；53%，23.9周）。分别在30日龄进行性腺切除的去卵巢S - D大鼠（47%，24.9周）和去势S - D大鼠（30%，24.8周）也对DMBA的易感性低得多。每组中观察到多种组织学类型，主要是恶性上皮、间充质或混合性肿瘤。雌性S - D大鼠（96%）乳腺组织中的癌性反应比雌性L - E大鼠（50%）高得多，而在雄性和性腺切除大鼠中非常低（10 - 20%）。相比之下，雌性和雄性L - E大鼠以及雄性S - D大鼠（43 - 50%）乳腺组织中的肉瘤性反应中等，其他组中较低（15 - 29%）。
