Basal gene expression in male and female Sprague-Dawley rat nasal respiratory and olfactory epithelium.

The nasal epithelium is an important target site for chemically induced toxicity and carcinogenicity. Experimental studies show that site-specific lesions can arise within the nasal respiratory or olfactory epithelium following the inhalation of certain chemicals. Moreover, gender differences in epithelial response are also reported. To better understand and predict gender differences in response of the nasal epithelium to inhaled xenobiotics, gene expression profiles from naive male and female Sprague-Dawley rats were constructed. Epithelial cells were manually collected from the nasal septum, naso- and maxillo-turbinates, and ethmoid turbinates of nine male and nine female rats. Gene expression analysis was performed using the Affymetrix Rat Genome 430 2.0 microarray. Surprisingly, there were few gender differences in gene expression. Gene ontology enrichment analysis identified several functional categories, including xenobiotic metabolism, cell cycle, apoptosis, and ion channel/transport, with significantly different expression between tissue types. These baseline data will contribute to our understanding of the normal physiology and selectivity of the nasal epithelial cells' response to inhaled environmental toxicants.