EVALUATION OF EXPOSURE LEVEL OF N-METHYL-BETA-CARBOLINE-3-CARBOXAMIDE(FG-7142), AN ANXIOGENIC AGENT IN HUMANS

beta-Carboline-3-carboxylic acid methylamide (FG 7142), an anxiogenic agent, has been detected in human urine. The urinary excretion level o f FG 7142 in non-smokers was found to be 0.503 +/- 0.25 ng per day (me an +/- S.D., n = 10), while that in smokers was found to be 2.418 +/- 0.384 ng per clay (n = 10). This suggests that humans are exposed to F G 7142 and that smokers are exposed to higher levels of FG 7142 than n on-smokers. Considering the previous findings that FG 7142 is present in cigarette smoke, indoor and outdoor air and smoke condensate of tre e leaves, humans may be exposed to FG 7142 via the airways and lungs, although we cannot exclude the possibility of exposure via foodstuffs. Results of animal experiments suggest that FG 7142 which enters the b loodstream is excreted into the urine via the kidneys within 24 h in a n unchanged form. Therefore, monitoring the level of FG 7142 in urine may be useful for monitoring the exposure level of FG 7142. (C) 1997 E lsevier Science Ltd.