The fate of (-)1-(benzofuran-2-yl)-2-propylaminopentane . HCl, (-)-BPAP, in rats, a potent enhancer of the impulse-evoked release of catecholamines and serotonin in the brain.

Our aim was to study the fate of (-)-1-(benzofuran-2-yl)-2-propylaminopentane .HCl [(-)-BPAP] in rats, using radio-labelled compound [(-)-BPAP-14C]. Radioactivity was measured by liquid scintillation technique and the tissue concentrations of radioactivity were calculated on the basis of the specific activity of (-)-BPAP-14C and the values are given in ngeq./g. Radioactivity was well absorbed after i.p., s.c. and oral treatment and Cmax has been reached at 30 to 60 min following drug administration. A second peak, detected at 4 hours, indicated enterohepatic circulation of the substance. The highest tissue levels of radioactivity were reached at 30 min following s.c. treatment. The time-related changes of radioactivity were measured in nine selected brain regions after s.c. administration of (-)-BPAP-14C. A similar distribution profile was observed in the brain regions with a peak level at 30 min. Radioactivity is preferentially eliminated through the urine, the secondary route of excretion was the stool. More than 90% of the substance was recovered in the excreta during 72 hours. The t1/2 beta was found to be 5.5 to 5.8 hours. (-)-BPAP was well absorbed and penetrated the brain. Its elimination was fast and enterohepatic circulation was observed in rats.