['The effects of 5-methoxypsoralen (5-MOP) on the distribution and metabolism of chemical carcinogens such as 2-aminofluorene (AF) has not been previously reported. In this study, the influences of 5-MOP on the metabolism of AF in Sprague-Dawley (SD) rats were investigated.', 'After receiving 5-MOP in 24 hours, AF was introduced into each animal by gastric intubation. After 12, 24, 48 and 72 hours the urine, feces, and cytosol of the liver, kidneys, stomach, colon, bladder and blood of rats were collected and assayed for AF and its metabolites by HPLC.', 'Compared to the control regimen, 5-MOP caused an increase of the metabolites excreted in urine and feces. The largest dose of metabolites were excreted between 48-72 hours. The major metabolite excreted in the urine was 9-hydroxy-AAF (9-OH-AAF) and in the feces was 7-hydroxy-AAF (7-OH-AAF). There was no time-effect for the tissues, and the liver was the main target organ for the AF and its metabolites. The major residual metabolite of AF in the liver, kidneys, stomach, colon and bladder was 7-OH-AAF. In blood it was 9-OH-AAF. The bladder had the lowest metabolic residue in tissues, and blood played the role of transportation but was not the target organ. 5-MOP decreased the concentration of AF and its residual metabolites of liver, stomach, kidneys, bladder and blood at various times.'] Does oral administration of 5-methoxypsoralen affect the distribution and metabolism of 2-aminofluorene in Sprague-Dawley rats?