Miyata Y, Babaya K, Oyasu R
Carcinogenesis. 1981;2(6):495-7. doi: 10.1093/carcin/2.6.495.
The present investigation was conducted to establish a working model to evaluate the role of potential modifiers (promoters and inhibitors) of urinary bladder carcinogenesis. A single dose (0.25 mg) of the carcinogen N-methyl-N-nitrosourea (MNU) when instilled directly into heterotopically transplanted urinary bladder (HTB) induced a 9% (2 of 22) incidence of urinary bladder tumors by 30 weeks in the urine free HTB environment, whereas repeated instillation of urine into the HTB after MNU treatment resulted in a 61% (14 of 23) incidence of these tumors. Three doses of MNU (0.25 mg/dose once a week for 3 weeks) induced 33% (6 of 18) and 89% (16 of 18) incidence of tumors, respectively, in the absence and presence of urine in the HTB. These data confirm our previous observation that normal urine enhances urinary bladder carcinogenesis, and are consistent with the notion that normal urine exerts a tumor promoting effect.
本研究旨在建立一个工作模型，以评估膀胱癌发生过程中潜在修饰因子（促进剂和抑制剂）的作用。将单剂量（0.25毫克）致癌物N-甲基-N-亚硝基脲（MNU）直接注入异位移植的膀胱（HTB）中，在无尿的HTB环境下，到30周时膀胱肿瘤的发生率为9%（22例中有2例），而在MNU治疗后向HTB中反复注入尿液，则这些肿瘤的发生率为61%（23例中有14例）。在HTB中，分别给予三剂MNU（0.25毫克/剂，每周一次，共3周），在无尿和有尿的情况下，肿瘤发生率分别为33%（18例中有6例）和89%（18例中有16例）。这些数据证实了我们之前的观察结果，即正常尿液会增强膀胱癌的发生，并且与正常尿液具有肿瘤促进作用的观点一致。
