Yoshimoto T, Inoue T, Iizuka H, Nishikawa H, Sakatani M, Ogura T, Hirao F, Yamamura Y
Cancer Res. 1980 Nov;40(11):4301-7.
Differential induction of squamous cell carcinomas, adenomas, and adenocarcinomas was observed in the lungs of male C57BL/6 and C3H/He mice after repeated intratracheal instillation of benzo(a)pyrene (BP) and charcoal powder suspended in 0.9% NaCl solution. when a high dose of BP (1.0 mg BP and 0.5 mg charcoal powder) was instilled intratracheally once a week for 8 weeks or when a low dose of BP (0.5 mg BP and 0.5 mg charcoal powder) was instilled once a week for 16 weeks, squamous cell carcinomas were induced in high incidence (77 to 87%) in the early period of observation, whereas pulmonary adenomas and adenocarcinomas were induced in low incidence (0. to 48%) in the late period of observation in both strains of mice. On the other hand, when a low dose of BP was instilled intratracheally once a week for 8 weeks, pulmonary adenomas and adenocarcinomas were induced in high incidence (76 to 91%), but squamous cell carcinomas were induced in low incidence (9 to 26%). These results show that a larger quantity of BP instilled intratracheally was needed for induction of squamous cell carcinomas than for induction of adenomas and adenocarcinomas in the lung of mice. Thus, when the carcinogen is administered to a single organ of a single mouse strain by the same route, different amounts of carcinogen have different effects on the incidences of various histological types of tumors.
在雄性C57BL/6和C3H/He小鼠的肺部，经气管内反复滴注悬浮于0.9%氯化钠溶液中的苯并(a)芘（BP）和炭粉后，观察到鳞状细胞癌、腺瘤和腺癌的差异诱导现象。当每周经气管内滴注一次高剂量BP（1.0毫克BP和0.5毫克炭粉），持续8周，或者每周滴注一次低剂量BP（0.5毫克BP和0.5毫克炭粉），持续16周时，在观察早期鳞状细胞癌的诱导发生率较高（77%至87%），而在观察后期两种品系小鼠的肺腺瘤和腺癌诱导发生率较低（0%至48%）。另一方面，当每周经气管内滴注一次低剂量BP，持续8周时，肺腺瘤和腺癌的诱导发生率较高（76%至91%），但鳞状细胞癌的诱导发生率较低（9%至26%）。这些结果表明，在小鼠肺部诱导鳞状细胞癌比诱导腺瘤和腺癌需要经气管内滴注更多量的BP。因此，当通过相同途径将致癌物给予单一小鼠品系的单一器官时，不同量的致癌物对各种组织学类型肿瘤的发生率有不同影响。
