Quantifying toxicological stress in amphibians: The influence of hydrophobicity on PAH and PCB elimination rates in northern leopard frogs (Rana pipens).

An experiment was conducted to determine if the elimination rates of various PCB and PAH congeners were controlled by hydrophobicity (log K ow) in adult northern leopard frogs (Rana pipiens). Frogs were subjected to intraperitoneal injections of one of the following three treatments: (a) 1:1:1 mixture of Aroclors 1242, 1254 and 1260; (b) an equimolar mixture of 17 unsubstituted PAHs; (c) a sunflower oil blank (control). Animals were sacrificed 1, 2, 4, 8, 16, 24 days after injection, followed by homogenization, chemical extraction and clean-up, and gas chromatographic analyses for remaining parent analytes. Elimination of PAH analytes were generally faster than that of PCBs. Comparison of PAH elimination rates to PCBs of corresponding log Kow gives indirect evidence of biotransformation (metabolism). The persistence and concomitant potential of PCB trophic transmission and narcosis, and the probable biotransformation of some PAHs into genotoxic metabolites could be related to amphibian population declines. The use of adult amphibians for PCB and PAH biomonitoring is also discussed. In addition, the first order, one compartment kinetic model commonly used in aquatic toxicology does not seem to apply to adult amphibians. (Abstract shortened by UMI.)Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2000 .W65. Source: Masters Abstracts International, Volume: 39-02, page: 0473. Adviser: G. Doug Haffner. Thesis (M.Sc.)--University of Windsor (Canada), 2000