Koller L D, Kerkvliet N I, Exon J H
Toxicol Pathol. 1985;13(1):50-7. doi: 10.1177/019262338501300107.
Sprague-Dawley rats were exposed to 0, 26, or 2600 ppm lead as lead acetate in drinking water for 76 weeks. At 28 weeks of lead exposure, a portion of each group was exposed simultaneously to 6.36 g/kg ethyl urea (EU) and 2.0 g/kg sodium nitrite (NaNO2) for a duration of 20 weeks, and then continued an additional 28 weeks on standard diet free of EU and NaNO2. The animals were observed for incidence, latency, and distribution of tumors. Rats exposed to 2600 ppm lead alone had 81% renal tumors, while rats given 2600 ppm lead in combination with EU/NaNO2 had a 50% incidence. Renal tumors did not occur in the EU/NaNO2 only or EU/NaNO2-26 ppm lead groups. The major tumor type found in EU/NaNO2-exposed rats was lymphosarcoma. Lead did not appear to be syncarcinogenic to the activity of ethylnitrosourea, the carcinogen formed by oral exposure to EU and NaNO2. The lead-induced renal neoplasms were histologically similar to those which occur spontaneously in man and, therefore, may serve as an animal model to study human disease.
将斯普拉格-道利大鼠暴露于饮用水中含0、26或2600 ppm醋酸铅形式的铅环境中76周。在铅暴露28周时，每组的一部分同时暴露于6.36 g/kg乙脲（EU）和2.0 g/kg亚硝酸钠（NaNO2）中持续20周，然后在不含EU和NaNO2的标准饮食下再持续28周。观察动物肿瘤的发生率、潜伏期和分布情况。仅暴露于2600 ppm铅的大鼠有81%发生肾肿瘤，而同时给予2600 ppm铅与EU/NaNO2的大鼠发生率为50%。仅暴露于EU/NaNO2组或EU/NaNO2加26 ppm铅组未发生肾肿瘤。在暴露于EU/NaNO2的大鼠中发现的主要肿瘤类型是淋巴肉瘤。铅似乎对口服EU和NaNO2形成的致癌物乙基亚硝基脲的致癌活性没有协同致癌作用。铅诱导的肾肿瘤在组织学上与人类自发发生的肾肿瘤相似，因此可作为研究人类疾病的动物模型。
