MNU诱导的大白鼠膀胱肿瘤模型的建立及病理学动态观察

目的观察N-甲基亚硝基脲（MNU）诱发SD大鼠膀胱癌模型的建立及病理学动态过程。方法MNU大鼠膀胱灌注每2周1次，每次2mg，共4次。随机观察实验第3、6、9、12、14周膀胱黏膜的改变，并在9、12和10周膀胱灌注^125I-UdR后行SPECT平面显像。结果膀胱灌注3周出现不典型增生，6周有原位癌改变，9周膀胱内有明显癌性肿块，12～14周膀胱内均出现乳头状癌或浸润性癌，9周的致癌率100．0％，组织学改变及病理学特征与人膀胱癌十分相似。SPECT显像见^125I-UdR膀胱灌注3d后诱癌组大鼠膀胱区放射性浓集。结论MNU灌注诱导大鼠膀胱癌模型为一理想的动物模型。致癌过程经历不典型增生、乳头状瘤形成和癌变动态过程。

The Establishment of Experimental Model of MNU-induced Bladder Cancers and Its Pathologically Dynamic Observations in Rats

Objective To investigate the establishment of experimental model of MNU-induced bladder cancers and its pathologically dynamic process in SD rats. Methods A double-weekly doses of 2 mg MNU each time for 4 weeks intravesicular administration were given. The changes of the bladder mucosa were studied through sample drawing at 3rd, 6th, 9th, 12th and 14th week and at the 9th, 12th and 14th after ^125I-UdR was performed intravesical instillation, the distribution of ^125I-UdR was estimated by SPECT scintigrams. Results administration and the carcinoma in situ at the Untypical hyperplasia could be seen after 3 weeks of 6 th week, distinctive tumor at the 9 th week, bladder papilloma or invasive carcinoma in the period from the 12th week to the 14th week were observed. The rate of carcinogenicity was 100 % after 9 weeks. The histological changes and the pathologic character were very similar with that in human bladder cancers. Radioactivity retained within bladder could be seen in the rats in the experimental group by SPECT scintigrams after intravesical instillation in 3 days. Conclusion Intravesical instillation of MNU in rats provides a useful model for experimental studies on bladder tumor. The carcinogenic process includes epithelial atypical hyperplasia, papilloma and carcinomatous changes.