Parton J W, Yount D J
Toxicology Research Laboratories, Lilly Research Laboratories, Greenfield, Indiana 46140, USA.
Environ Mol Mutagen. 1995;26(2):147-54. doi: 10.1002/em.2850260208.
The unscheduled DNA synthesis (UDS) assay has been used extensively for the in vitro detection of DNA damage caused by compound exposure. However, the in vitro UDS assay has been insensitive for the detection of certain chemicals, particularly nitroaromatic compounds, that are positive in bacterial mutation assays. Recently, studies have been reported which describe alterations in the hepatocyte membrane following collagenase perfusion. Independently, a method for serum-free tissue culture has been developed which results in the up-regulation of cell surface receptors and which may restore membrane functions. Fourteen compounds, including seven nitroaromatics, were evaluated in the in vitro UDS assay employing a serum-free procedure. Five compounds that were previously reported positive in the standard in vitro UDS assay were also found positive using the serum-free method. In addition, five of the nitroaromatic compounds produced positive results with the serum-free method. 1-Methyl-3-nitro-1-nitrosoguanidine and 2-acetylaminofluorene, routinely used as positive controls in the UDS assay, showed greater activity in the serum-free assay. These results suggest that the use of serum-free media improves the sensitivity of the in vitro UDS assay and that the serum-free procedure potentially offers an effective alternative to the more labor intensive and more costly in vivo UDS assay.
非程序性DNA合成（UDS）试验已被广泛用于体外检测化合物暴露引起的DNA损伤。然而，体外UDS试验对某些在细菌突变试验中呈阳性的化学物质，特别是硝基芳香化合物的检测不敏感。最近，有研究报道了胶原酶灌注后肝细胞膜的变化。另外，已经开发出一种无血清组织培养方法，该方法可导致细胞表面受体上调，并可能恢复膜功能。采用无血清程序在体外UDS试验中评估了14种化合物，包括7种硝基芳香化合物。在标准体外UDS试验中先前报道呈阳性的5种化合物，使用无血清方法也呈阳性。此外，5种硝基芳香化合物用无血清方法产生了阳性结果。在UDS试验中常规用作阳性对照的1-甲基-3-硝基-1-亚硝基胍和2-乙酰氨基芴，在无血清试验中显示出更高的活性。这些结果表明，使用无血清培养基可提高体外UDS试验的灵敏度，并且无血清程序可能为更耗费人力和成本更高的体内UDS试验提供一种有效的替代方法。
