Norpoth K, Stücker W, Krewet E, Müller G
Institute of Hygiene and Occupational Medicine, University of Essen, Federal Republic of Germany.
Int Arch Occup Environ Health. 1988;60(3):163-8. doi: 10.1007/BF00378692.
From preliminary experiments it was known that radiolabelled benzene and some of its metabolites during its metabolic activation process produce different in vitro DNA-phenyladducts in mitoplasts. As we reported previously at least one of these adducts, N-7-phenylguanine, is excreted in the urine of rats in measurable amounts, probably through an excision-repair mechanism after an inhalation experiment. Now we found, after i.p. application of benzene in the urine of rats, a compound separated by cation-exchange chromatography that behaves like a synthesized N-7-phenylguanine reference substance with respect to its retention index and the UV-absorption. This finding could be confirmed by HPLC-measurements with reversed-phase carrier materials. Silylation and gas chromatographic/mass spectrometric (GC/MS) separation of the fraction, which contains the phenylguanine, revealed that these fractions contain further phenyl adducts. Furthermore we studied the time-dependent excretion of the DNA-base adduct. Surprisingly the excretion dropped to zero on the fourth day and showed a new increase thereafter.
从初步实验可知，放射性标记的苯及其在代谢活化过程中的一些代谢产物在有丝分裂体中会产生不同的体外DNA - 苯加合物。正如我们之前所报道的，在吸入实验后，这些加合物中至少有一种，即N - 7 - 苯基鸟嘌呤，会以可测量的量从大鼠尿液中排出，可能是通过切除修复机制。现在我们发现，在大鼠经腹腔注射苯后，通过阳离子交换色谱法分离出一种化合物，就其保留指数和紫外吸收而言，其行为类似于合成的N - 7 - 苯基鸟嘌呤参考物质。这一发现可以通过使用反相载体材料的高效液相色谱测量得到证实。对含有苯基鸟嘌呤的馏分进行硅烷化和气相色谱/质谱（GC/MS）分离，结果表明这些馏分还含有其他苯基加合物。此外，我们研究了DNA碱基加合物随时间的排泄情况。令人惊讶的是，排泄量在第四天降至零，此后又出现新的增加。
