Abstract
It has been shown that norharman and harman, present in our environment, may act as genotoxic compounds in human body. In order to have an insight of the extents of exposure to these β-carbolines, we measured their levels in human urine. Samples of 24-hr urine were collected from ten healthy volunteers eating a normal diet and three patients receiving parenteral alimentation. The urine samples were separated by blue cotton treatment, cation exchange IONEX column chromatography and HPLC on a semi-preparative ODS column. The contents of norharman and harman in the partially purified materials were determined by HPLC with a fluorometric detector. Norharman and harman were detected in all 24-hr urine samples from healthy volunteers at levels of 9.3-33.5ng and 97.7-298ng, respectively. These β-carbolines were also found to be present in the urine of the three patients and their levels in the 24-hr urine were comparatively lower than those in urine of healthy volunteers eating normal diet. After changing from parenteral alimentation to diet, the two β-carboline levels in urine increased in two of the three patients. From the above results, it is suggested that humans are continuously exposed to norharman and harman derived endogenously and exogenously.
