Griesemer R A, Nettesheim P, Marchok A C
Cancer Res. 1976 Jul;36(7 PT 2):2659-64.
Hyperplastic-metaplastic lesions were produced in transplanted rat tracheas by exposure to 310 or 75 mug 7,12-dimethylbenz(a)anthracene or to 650 mug benzo(a)pyrene delivered over a 2-week exposure period. Tissue recovery was studied for up to 16 weeks. After cessation of carcinogen exposure, most of the hyperplastic-metaplastic epithelium was rapidly replaced by mucociliary epithelium. In the 7,12-dimethylbenz(a)anthracene-exposed tracheas, a few mataplastic foci remained at 4 and 8 weeks. In all 3 exposure groups, portions of the mucosa were occupied by atrophic-pleomorphic epithelium that persisted throughout the observation period. The significance of these lesions in the evolution of neoplasia is as yet unknown. In vitro studies with epithelial cells derived from 7,12-dimethylbenz(a)anthracene-exposed tracheal transplants revealed that some cells have acquired a growth potential that is markedly different from that of normal mucociliary epithelium. This altered in vitro growth potential of epithelial cells may be an early indicator of an important event in the evolution of epithelial transformation in vivo.
通过在2周的暴露期内给予310或75微克的7,12-二甲基苯并(a)蒽或650微克的苯并(a)芘，在移植的大鼠气管中产生增生-化生病变。对组织恢复情况进行了长达16周的研究。在致癌物暴露停止后，大多数增生-化生上皮迅速被黏液纤毛上皮取代。在暴露于7,12-二甲基苯并(a)蒽的气管中，在4周和8周时仍有一些化生灶残留。在所有3个暴露组中，部分黏膜被萎缩-多形性上皮占据，且在整个观察期内持续存在。这些病变在肿瘤形成过程中的意义尚不清楚。对来自暴露于7,12-二甲基苯并(a)蒽的气管移植的上皮细胞进行的体外研究表明，一些细胞获得了与正常黏液纤毛上皮明显不同的生长潜能。上皮细胞这种体外生长潜能的改变可能是体内上皮转化过程中一个重要事件的早期指标。
