Pulmonary Carcinogenesis in the F344 and Wistar Rat after Inhalation of Plutonium Dioxide

Autor: C. L. Sanders, D. L. Lundgren
Rok vydání: 1995
Předmět:
Zdroj: Radiation Research. 144:206
ISSN: 0033-7587
DOI: 10.2307/3579260
Popis: Pulmonary carcinogenesis was compared in female F344 and Wistar rats after inhalation of high-fired {sup 239}PuO{sub 2}. Plutonium particle aggregation, as determined by quantitative light and scanning electron microscopic autoradiography, was greater for the F344 strain than for the Wistar strain. The median survival times were similar in control and low-dose (0.8-1.0 Gy) groups of both strains, but were significantly decreased in the high-dose (34-37 Gy) groups of both strains. Squamous metaplasia was not found in control or low-dose groups of either strain, but was found in 62-65% of high-dose groups of both strains. Adenomatous metaplasia was considerably higher in control and low-dose groups of F344 rats than in Wistar rats. A total of 87 lung tumors were found in 140 exposed F344 rats and 46 lung tumors in 176 exposed Wistar rats. The incidence of lung tumors in F344 rats was 1.7% in controls, 20% in the low-dose group and 82% in the high-dose group. The incidence of lung tumors in Wistar rats was 0.1% in controls, nil in the low-dose group and 68% in the high-dose group. The median survival times of rats of both strains in the high-dose groups that died with lung tumors were greater comparedmore » with rats in these groups that died without lung tumors. In contrast, these differences did not occur among rats in the low-dose groups. The absolute risk was 1900 lung tumors per 10{sup 4} Rat-Gy for F344 rats but about 210 lung tumors per 10{sup 4} Rat-Gy for high-dose groups of both strains. The adenomatous tumor phenotype predominated in the F344 strain, while the squamous tumor phenotype predominated in the Wistar strain. Risk of squamous tumors was similar for both strains. Overall, the F344 strain appears to be more {open_quotes}sensitive{close_quotes} than the Wistar strain to formation of lung tumors at low to moderate doses from inhaled {sup 239}PuO{sub 2}. 31 refs., 1 fig., 7 tabs.« less
Databáze: OpenAIRE