Meeting Abstract

P2.110  Wednesday, Jan. 5  Detoxification Enzyme Expression in Nasal Epithelium of Woodrats HALE, A.J.*; SKOPEC, M.M.; DEARING, M.D.; Weber State University; Weber State University; University of Utah andrewhale@mail.weber.edu

Multiple species of woodrats (genus Neotoma) consume plants such as juniper (Juniperous monosperma) and creosote (Larrea tridentata) that produce toxic plant secondary compounds (PSC). Some of the PSC produced by these plants are volatile and therefore enter the nasal passages. Nasal passages lie very close to the brain with only the nasal epithelium protecting the olfactory bulb from inhaled toxins. We hypothesized that the nasal epithelium may be playing an important role in metabolizing the volatile PSC before they reach the olfactory bulb. Western blotting was used to compare the amount of two detoxification enzymes cytochrome P450 2B (CYP2B) and glutathione S-transferase (GST) in the nasal epithelium and olfactory bulbs of three species of woodrats (Neotoma bryanti, Neotoma lepida, and Neotoma albigula) eating one of three diets (control, 2% creosote or 25% juniper). CYP2B and GST were not detected in the olfactory bulbs of any of the woodrats. In contrast levels of CYP2B in the nasal epithelium in relation to expression in the liver ranged from 58% in creosote fed N. lepida, to 184% in control fed N. bryanti. Expression of GST in the nasal epithelium in relation to expression in the liver ranged from 8% in control fed N. bryanti, to 20% in creosote fed N. lepida. Woodrats fed a creosote diet had lower relative expression of CYP2B but higher relative expression of GST compared to animals fed a control diet (p<0.05). Woodrats fed the juniper diet had higher relative expression of CYP2B and similar levels of GST compared to control fed animals (p<0.05). We conclude that the nasal epithelium is protecting the olfactory bulb from volatile PSC and that the expression of CYP2B and GST in the nasal epithelium differs depending on the PSC profile of the diet consumed.