Benzidine is recognized as a urinary bladder carcinogen in humans. The use of benzidine in industries was prohibited because of its carcinogenecity, but, production and usage of benzidine based dye was still permitted in most countries. This study was performed to compare the excretory patterns of urinary metabolites between benzidine-based dye(Direct Black 38) and benzidine in rats.
Benzidine-based dye was administered orally at the doses of 0.3, 0.5, 0.7 mmol/㎏ and benzidine was administered orally at the doses of 0.2, 0.4, 0.6 mmol/㎏ into Sprague-Dawley rats. To analyze benzidine and its metabolites, the high performance liquid chromatography with an electric chemical and ultraviolet detector were used. N-acetylbenzidine, N,N‘-diacetylbenzidine and 4-aminobiphenyl were identified in the urine of the rats receiving dye and benzidine. The excreted amount of the urinary benzidine from dye was almost 1/10 of that from benzidine. Excretion rates of metabolites were more prolonged in the dye receiving group than those of the benzidine group. Peak concentration time of urinary N,N’-diacetylbenzidine was more prolonged than other metabolites in both groups. The excreted amount of N-acetylbenzidine was more than the others in both group.
These results suggested that N-acetylbenzidine may be an useful Biological exposure index for benzidine-based dye.
|