Inoue O, Seiji K, Watanabe T, Kasahara M, Nakatsuka H, Yin S N, Li G L, Cai S X, Jin C, Ikeda M
Center of Occupational Medicine, Tohoku Rosai Hospital, Sendai, Japan.
Int Arch Occup Environ Health. 1988;60(1):15-20. doi: 10.1007/BF00409373.
The exposure intensity during a shift and the metabolite levels in the shift-end urine were examined in male workers exposed to either benzene (65 subjects; the benzene group), toluene (35 subjects; the toluene group), or a mixture of both (55 subjects; the mixture group). In addition, 35 non-exposed male workers (the control group) were similarly examined for urinary metabolites to define background levels. A linear relationship was established between the intensity of solvent exposure and the corresponding urinary metabolite levels (i.e. phenol, catechol and quinol from benzene, and hippuric acid and o-cresol from toluene) in each case when one of the three exposed groups was combined with the control group for calculation. Comparison of regression lines in combination with regression analysis disclosed that urinary levels of phenol and quinol (but not catechol) were lower in the mixture group than in the benzene group when the intensities of exposure to benzene were comparable, indicating that the biotransformation of benzene to phenolic compounds (excluding catechol) in man is suppressed by co-exposure to toluene. Conversely, metabolism of toluene to hippuric acid was suppressed by benzene co-exposure. Conversion of toluene to o-cresol was also reduced by benzene, but to a lesser extent. The significance of the present findings on the mutual suppression of metabolism between benzene and toluene is discussed in relation to solvent toxicology and biological monitoring of exposure to the solvents.
对接触苯的男性工人（65名受试者；苯组）、接触甲苯的男性工人（35名受试者；甲苯组）或同时接触苯和甲苯的男性工人（55名受试者；混合组），测定了一个班次期间的接触强度以及班次结束时尿液中的代谢物水平。此外，对35名未接触溶剂的男性工人（对照组）也进行了类似的尿液代谢物检测，以确定背景水平。在将三个接触组中的任何一组与对照组合并进行计算时，每种情况下均在溶剂接触强度与相应尿液代谢物水平（即苯代谢产生的苯酚、儿茶酚和对苯二酚，以及甲苯代谢产生的马尿酸和邻甲酚）之间建立了线性关系。结合回归分析对回归线进行比较发现，当苯的接触强度相当时，混合组中苯酚和对苯二酚（而非儿茶酚）的尿液水平低于苯组，这表明同时接触甲苯会抑制人体中苯向酚类化合物（不包括儿茶酚）的生物转化。相反，同时接触苯会抑制甲苯向马尿酸的代谢。苯也会使甲苯向邻甲酚的转化减少，但程度较小。结合溶剂毒理学和溶剂接触的生物监测，讨论了苯和甲苯代谢相互抑制的当前研究结果的意义。
