| Popis: |
In experiments to determine the toxicokinetics of polycyclic aromatic hydrocarbons (PAHs) in lungs at environmentally realistic levels, a technique to measure metabolites in tissueat subfemtomolar concentrations was needed. Postexposure blood concentrations of \[3H]benzo\[a]pyreneand\[3H]pyrenemetabolites were determined after intratracheal instillation of 10 ng in three beagle dogs. 3H20 was distilled from samples in vacuo, and the residual radioactivity was fractionated into water-soluble, bound (pellet-associated), and organic-extractable fractions. Radioactivity in the pellet and aqueous fraction was determined by complete combustion and subsequent liquid scintillation counting. The organicsoluble fractions, which contained the metabolites of interest, also contained lipids that were inseparable from the highly lipophilic PAHs. The lipids were saponified using CaO, extracted with ethyl acetate, resuspended in methanol, and fractionated using RP-HPLC. Metabolites were identified by coelution with authe... |
