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USE OF MULTIPHOTON LASER SCANNING MICROSCOPY TO IMAGE BENZO[A]PYRENE AND METABOLITES IN FISH EARLY LIFE STAGES
Citation:
Hornung, M. W., K. M. Flynn, R. D. Johnson, P. M. Cook, AND J W. Nichols. USE OF MULTIPHOTON LASER SCANNING MICROSCOPY TO IMAGE BENZO[A]PYRENE AND METABOLITES IN FISH EARLY LIFE STAGES. Presented at Photonics West, San Jose, CA, January 24-29, 2004.
Description:
Multiphoton laser scanning micrsocopy holds promise as a tool to study the tissue distribution of environmental chemical contaminants during fish early life stage development. One such chemical for which this is possible is benzo[a]pyrene (BaP), a polyaromatic hydrocarbon that absorbs strongly at UV wavelengths and is amenable to multiphoton excitation. BaP is metabolized to hydroxylated metabolites, which are further modified through enzymatic conjugation with glucuronide or sulfate moieties. These metabolites have spectral characteristics similar to BaP, which presents a challenge in following the tissue distribution of individual chemicals throughout development. To differentiate between parent compound and metabolites, multi-photon spectra of parent and several major metabolites were determined using a tunable Ti:Sapphire laser. BaP and metabolites showed two primary fluorescent peaks following excitation at 755 and 800 nm. At wavelengths greater than 820 nm, there was no excitation of BaP or 3-SO4-BaP, however, the 3-OH-BaP showed a third strong spectral peak between 840 and 860 nm. The spectra from 740 nm to 880 nm revealed differences at the longer wavelengths that could be used to detect the production of the primary metabolite, 3-OH-benzo[a]pyrene, in the presence of parent chemical. Thus, utilizing different multiphoton excitation spectral characteristics of specific PAHs can provide a means to follow the tissue distribution of parent and metabolite in situ in the developing organism. This abstract does not necessarily reflect EPA policy.