Journal of Chemical Ecology

, 33:2111 | Cite as

Xenobiotic Metabolism of Plant Secondary Compounds in Oak (Quercus Agrifolia) by Specialist and Generalist Woodrat Herbivores, Genus Neotoma

  • Shannon L. Haley
  • John G. Lamb
  • Michael R. Franklin
  • Jonathan E. Constance
  • M. Denise Dearing


The challenge of consuming plant compounds that are recognized to have toxic physiological effects is an unavoidable consequence of an herbivorous diet and requires mechanisms to metabolize and eliminate them after consumption. We took a pharmacological approach to understanding how an oak (Quercus agrifolia) specialist (Neotoma macrotis) and generalist (N. lepida) herbivores process the same dietary toxins. Oak contains polyphenolic compounds considered toxic to most other mammals. N. macrotis includes up to 85% of oak in their diet. N. lepida includes oak as a portion of the diet but is considered a generalist in areas where sympatric with N. macrotis. Xenobiotic metabolizing enzyme activities of N. macrotis and N. lepida were investigated after animals were fed a 70% oak diet and a toxin-free control diet. Biotransformation activities of five major enzymes [cytochrome P450s (CYP), NAD(P)H/quinone oxidoreductase (QOR), UDP-glucuronosyltransferase (UGT), sulfotransferase (SULT), and glutathione S-transferase (GST)] and three specific CYP isozymes (CYP1A, CYP2B, and CYP3A) were investigated. The results indicate that, with the exception of CYP2B induction, N. macrotis and N. lepida enzyme activities are not changed by an oak diet. The major differences in enzyme activities were constitutive. The specialist, N. macrotis, had higher constitutive activity of QOR, UGT, and GST. The generalist, N. lepida, had higher constitutive activity levels of CYP1A and SULT.


Cytochrome P450 monooxygenases Conjugation Neotoma Specialist Herbivore 



We thank committee members Dr. G. Yost, Dr. F. Goller, Dr. D. Feener for their invaluable input. We also thank Dr. J. Sorensen, Dr. M. Skopec and Ann-Marie Torregrossa for critical reading of the manuscript and the undergraduates in Dr. Dearing’s lab, especially Katie Young and John Matthews, for assistance with feeding, tissue collection as well as collection and maintenance of woodrats. Research was supported by National Science Foundation (NSF IBN 023402).


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Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Shannon L. Haley
    • 1
  • John G. Lamb
    • 2
  • Michael R. Franklin
    • 2
  • Jonathan E. Constance
    • 2
  • M. Denise Dearing
    • 1
  1. 1.Department of BiologyUniversity of UtahSalt Lake CityUSA
  2. 2.Department of Pharmacology and ToxicologyUniversity of UtahSalt Lake CityUSA

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