Davis B R, Whitehead J K, Gill M E, Lee P N, Butterworth A D, Roe F J
Br J Cancer. 1975 Apr;31(4):469-84. doi: 10.1038/bjc.1975.87.
SPF rats were exposed to the smoke from 10 cigarettes per week from the age of 10 weeks until they died. Survival, body weight, tumour incidence and histopathological appearances of the lungs were compared with those for untreated sham exposed rats. Two further groups were given a single dose of 3,4-benzyprene (BP) by intratracheal instillation. One of these was then exposed to the smoke of 10 cigarettes per week till death. Compared with untreated or sham exposed rats, exposure to smoke was associated with a significant reduction in incidence of mammary tumours. Exposure to smoke was associated with an increasing incidence of collections of macrophages laden with golden-brown pigment (GBM) and of areas of cuboidal or columnar metaplasia (CCM) or squamous metaplasia (Sq.M) of alveolar epithelium. In control rats there was virtually no GBM, a low incidence of CCM and Sq.M. Four out of 406 smoke exposed rats which came to post mortem had squamous neoplasms in the lungs, 3 having lesions of doubtful malignancy and one having a squamous carcinoma. In contrast, no squamous neoplasms were seen in 197 control rats. This difference was not statistically significant. The findings in rats given a single dose of BP were, in all the above respects, similar to those in untreated rats, except that one developed a squamous carcinoma of the lung. The effects of a single dose of BP followed by smoke exposure were in general similar to those of smoke exposure only. Three rats on this treatment regimen developed squamous cancers of the lung. None of the treatments increased the incidence of adenomata of the lungs. The results are discussed in relation to other studies of the effects of smoke exposure on rats and other species.
将10周龄的SPF大鼠每周暴露于10支香烟的烟雾中，直至其死亡。将其生存率、体重、肿瘤发生率以及肺部的组织病理学表现与未处理的假暴露大鼠进行比较。另外两组通过气管内滴注给予单剂量的3,4-苯并芘（BP）。其中一组随后每周暴露于10支香烟的烟雾中直至死亡。与未处理或假暴露的大鼠相比，暴露于烟雾与乳腺肿瘤发生率显著降低有关。暴露于烟雾与充满金棕色色素（GBM）的巨噬细胞聚集以及肺泡上皮立方或柱状化生（CCM）或鳞状化生（Sq.M）区域的发生率增加有关。在对照大鼠中，几乎没有GBM，CCM和Sq.M的发生率较低。406只接受烟雾暴露的大鼠中有4只在死后肺部出现鳞状肿瘤，3只具有可疑恶性病变，1只患有鳞状癌。相比之下，197只对照大鼠中未观察到鳞状肿瘤。这种差异无统计学意义。在上述所有方面，给予单剂量BP的大鼠的结果与未处理的大鼠相似，只是有一只发生了肺鳞状癌。单剂量BP后再暴露于烟雾的效果总体上与仅暴露于烟雾的效果相似。接受这种治疗方案的3只大鼠发生了肺鳞状癌。所有处理均未增加肺腺瘤的发生率。结合其他关于烟雾暴露对大鼠和其他物种影响的研究对结果进行了讨论。
