ABSTRACT
INTRODUCTION “Biomarker” is a general term for a specific measurement of an interaction between a biological system and an environmental agent (1). In human epidemiological studies, the ideal biomarker is highly specific for the agent of concern and, further, can be measured by noninvasive means, such as measuring chemical metabolites in urine or hair. In terms of biomarkers of nasal toxicity in experimental animals, this chapter discusses several in vivo measurements that can properly be considered biomarkers. Also discussed are endpoints that do not fit the classical definition of biomarkers because they are assessed on tissues after sacrifice of the animals, but are nonetheless indicative of exposure to various compounds. In vivo biomarkers will include imaging and behavioral endpoints, whereas postmortem “biomarkers” of nasal epithelial responses to environmental agents will include induction or inhibition of various proteins; changes in the structure of the nasal turbinates; alterations in gene expression and protein expression; and DNA and protein adducts.
