The effects of 5-hydroxypyrimidine derivatives SNK-411 (2-isobutyl-4,6-dimethyl-5-hydroxypyrimidine) and SNK-578 (2-isobutyl-4,6-dimethyl-5-hydroxypyrimidine chlorohydrate) on the tumor growth and survival of male C57BL/6 mice with transplanted Lewis lung epidermoid carcinoma (LLC) were studied in animals receiving intraperitoneal treatment on days 2-15 of tumor development. Compound SNK-578 in a dose of 10 mg/kg significantly inhibited tumor growth (by 3.6 times; 72.2%) in 7 days after the treatment was discontinued, while compound SNK-411 in a dose of 25 mg/kg only negligibly reduced tumor volume (by 41.7%). A combination of course of SNK-411 (25 mg/kg) and single intraperitoneal dose of doxorubicin (4 mg/kg) significantly inhibited the tumor growth (by 2.2 times; 55.2%), while the combination of SNK-578 (10 mg/kg) with doxorubicin (4 mg/kg) was in fact ineffective. The median survival of animals with untreated LLC was 28 days. Median survival of mice injected with SNK-578 (10 mg/kg) was 43 days, hence, the lifespan of mice with LLC was by 38.6% longer after the treatment. Two of ten mice in this group developed no tumors.

中文翻译：

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5-羟基嘧啶衍生物对表皮样肺癌C57BL/6小鼠肿瘤生长和寿命的影响

5-羟基嘧啶衍生物 SNK-411（2-异丁基-4,6-二甲基-5-羟基嘧啶）和 SNK-578（2-异丁基-4,6-二甲基-5-羟基嘧啶氯水合物）对肿瘤生长和在肿瘤发展的第 2-15 天接受腹膜内治疗的动物中研究了移植了路易斯肺表皮样癌 (LLC) 的雄性 C57BL/6 小鼠的存活率。10 mg/kg剂量的化合物SNK-578在停止治疗后7天内显着抑制肿瘤生长（3.6倍；72.2%），而25 mg/kg剂量的化合物SNK-411仅微不足道地减少肿瘤量（增加 41.7%）。SNK-411 (25 mg/kg) 和单次腹腔注射多柔比星 (4 mg/kg) 的组合显着抑制肿瘤生长（2.2 倍；55.2%），而 SNK-578 (10 mg/kg) 与多柔比星 (4 mg/kg) 的组合实际上是无效的。未经治疗的 LLC 动物的中位生存期为 28 天。注射 SNK-578 (10 mg/kg) 的小鼠的中位存活时间为 43 天，因此，治疗后 LLC 小鼠的寿命延长了 38.6%。该组中的十只小鼠中有两只没有发生肿瘤。