PHARMACOKINETICSOFN'-NITROSONORNIC~TINEAND 4-(METHYLNITROSAMINO)-l-(3-PYRIDYL)-1-BUTANONEIN h LABORATORYANIMALS*

SUMMARY The pharmacokinetics of IV’-nitrosonomicotme (NNN jand 4-(methylnitrosamino)-1-(3-pyridyl)-l-butanone (NNK) in the Syrian golden hamster, the CD-1 mouse, and the baboon were compared to the pharmacokinetics in the Fischer rat. The formation and biological half-life of 4-(methylnitrosamino)1-(3-pyridyl)-1-butanol (NNAL), the major metabolite of NNK, was also studied in these animal species. The biological half-life of NNN in these 4 animal species ranged from 0.24 h to.3.06 h, that of NNK from 0.21 h to 0.43 h and NNAL from 0.48 h to 2.9 h. The pharmacokinetic data obtained in the baboon suggest that treatment with NNN and NNK causes an enzyme induction which accelerates the rate of elimination of these compounds.