Sheu C J, Lee J K, Rodriguez I, Randolph S C
Genetic Toxicology Branch, Food and Drug Administration, Washington, DC 20204.
Drug Chem Toxicol. 1991;14(1-2):113-26. doi: 10.3109/01480549109017871.
Because of limited inherent capacity to metabolize chemicals to their reactive form, the BALB/3T3 transformation assay using clone A31-1-1 cells requires metabolic supplementation with rodent liver homogenate preparations (S-9). Activation by S-9 is limited, however, by its cytotoxicity to the cells, thus necessitating a reduction in treatment time from the usual 24-72 to 1-4 hr. With cyclophosphamide (CP) as a test chemical, we were able to increase the treatment time to 24 hr by using lower concentrations of cofactors and S-9 prepared from the livers of untreated rats. Statistically significant increases in transformed foci were induced in cultures treated with 50 or 100 micrograms CP/ml in the presence of 100 or 200 micrograms of uninduced rat liver S-9/ml and 76 or 380 micrograms each of NADH, NADP, NADPH, and glucose-6-phosphate per ml of incubation medium.
由于将化学物质代谢为其活性形式的内在能力有限，使用克隆A31 - 1 - 1细胞的BALB / 3T3转化试验需要用啮齿动物肝脏匀浆制剂（S - 9）进行代谢补充。然而，S - 9的激活受到其对细胞的细胞毒性的限制，因此需要将处理时间从通常的24 - 72小时减少到1 - 4小时。以环磷酰胺（CP）作为测试化学物质，我们能够通过使用较低浓度的辅因子和从未经处理的大鼠肝脏制备的S - 9，将处理时间延长至24小时。在用50或100微克CP / ml处理的培养物中，在每毫升孵育培养基中存在100或200微克未诱导的大鼠肝脏S - 9以及76或380微克的NADH、NADP、NADPH和葡萄糖 - 6 - 磷酸的情况下，诱导出具有统计学意义的转化灶增加。
