Olfactory Mucosa: Composition, Enzymatic Localization, and Metabolism

This chapter examines the basic structure and cell types of the olfactory mucosa, and then focuses primarily on the enzymatic capacity of the tissue. The anatomic characteristics generally common to all species are outlined and followed by a brief discussion of interspecies variability in the magnitude, localization, or occurrence of these characteristics. The identity and localization of nasal enzymes and their metabolic capacities are compared across several species. The potential for these enzymes to modulate the toxicity of xenobiotics and to influence tissue function, including homeostasis and odor signal detection, is discussed. The chapter describes the complexity in the composition and regulation of the major known biotransformation enzymes in the olfactory mucosa. Additionally, it discusses various physiological and pathological processes in which nasal metabolic activity is thought to play a role.