Oghiso Y, Yamada Y, Ishigure N, Fukuda S, Iida H, Yamada Y, Sato H, Koizumi A, Inaba J
Division of Radiotoxicology, National Institute of Radiological Sciences, Chiba, Japan.
J Radiat Res. 1994 Dec;35(4):222-35. doi: 10.1269/jrr.35.222.
Female Wistar strain rats were exposed to a single inhalation of a submicron-size aerosol of high-fired 239PuO2 to investigate pulmonary carcinogenesis during lifespan periods. The absorbed lung doses of the exposed animals ranged from 0.6 to 12 Gy and were well correlated with the initial lung deposition (ILD) of 0.1 to 2.3 kBq. Survival and induction of primary lung tumors in 116 exposed rats were compared with those in 56 untreated control rats in respect to lung doses received. Mean survival time was greatly reduced, and the cumulative incidence of total lung tumors was markedly increased to 90-100% in rats that received more than 4 Gy, whereas of the controls only one animal (1.8%) died of primary lung tumors. Primary but benign adenomas were present in exposed animals given 1.0 Gy or less, and the incidence of adenomas was 22-25% at 4-5 Gy, but decreased sharply to 3-5% at 6-8 Gy. In contrast, no malignant carcinomas, including adenocarcinomas, adenosquamous carcinomas and squamous cell carcinomas, developed at a dose of less than 1.0 Gy, whereas they were present in 75% or more of the rats given 4-10 Gy, but only in 55% at 12 Gy. Although there were no clear differences in the dose and time required for induction among the carcinoma types, all tended to develop in earlier periods after inhalation than adenomas. Despite the limited number of exposed animals that received lower doses, results suggest that malignant lung carcinomas are highly and early induced and have a different dose-effect relationship than benign adenomas at doses of more than 1 Gy after inhalation exposure to 239PuO2.
将雌性Wistar品系大鼠单次吸入高焙烧239PuO2的亚微米级气溶胶，以研究其终生期的肺致癌作用。暴露动物的肺吸收剂量范围为0.6至12 Gy，与初始肺沉积量（ILD）0.1至2.3 kBq密切相关。将116只暴露大鼠的生存情况和原发性肺肿瘤的诱发情况与56只未处理的对照大鼠所接受的肺剂量进行比较。平均生存时间大幅缩短，接受超过4 Gy的大鼠中，肺肿瘤的累积发生率显著增加至90 - 100%，而对照组中只有一只动物（1.8%）死于原发性肺肿瘤。接受1.0 Gy及以下剂量的暴露动物出现原发性但为良性的腺瘤，4 - 5 Gy时腺瘤发生率为22 - 25%，但在6 - 8 Gy时急剧降至3 - 5%。相比之下，剂量低于1.0 Gy时未发生包括腺癌、腺鳞癌和鳞状细胞癌在内的恶性癌，而在接受4 - 10 Gy的大鼠中，恶性癌的发生率在75%及以上，但在12 Gy时仅为55%。尽管低剂量暴露动物数量有限，但结果表明，吸入239PuO2后，剂量超过1 Gy时，恶性肺癌的诱发具有高发性和早期性，且与良性腺瘤具有不同的剂量 - 效应关系。
