Distribution of 3H-8-MOP and its Metabolites in Rat Organs after a Single Oral Administration

Concentrations of 3H-8-metboxypsoralen (MOP), its lipid and water soluble metabolites and tritiated water have been measured in rat serum, liver, kidney and skin, using liquid scintillation, thin-layer chromatography and other techniques.Radioactivity in whole blood, plasma, ovary, adrenals and pancreas has also been measured.The radioactivity has been measured up to 1week after medication, whilst 3H-8-MOP and metabolite concentrations have been measured from 10mm to 24hr after medication with a single dose of 1mg 3 H-8-MOP in solution/kg bodyweight.Maximum 8-MOP concentrations were seen from 10 to 30min after dosing. The concentrations in μg/kg 10 min, 2hr, and 24hr after medication were as follows: serum—686, 57, 2.1; liver—489, 45, 3.3; kidney—1708, 139, 4.3; and skin—55, 16, 3.8. The concentrations of water soluble metabolites were very high in the liver and only slightly lower in the kidney. The concentrations of these metabolites might accumulate after doses repeated 4 times a week. 3H-8-MOP and its other metabolites would not show similar accumulation. Most of the radioactivity present after 1week is due to tritiated water