IMMUNOHISTOCHEMICAL LOCALIZATION OF A CYTOCHROME-P-450 ISOZYME IN HUMAN NASAL-MUCOSA - AGE-RELATED TRENDS

Immunoperoxidase staining with an antibody to cytochrome P-450 (NMa) w as used to investigate the localization of this isozyme in the human n asal mucosa. Olfactory mucosa was identified by staining of olfactory receptor cells with an antibody to olfactory marker protein. Immunorea ctivity to NMa was localized in sustentacular cells in the olfactory e pithelium, and in Bowman's gland acinar cells and vascular endothelial cells in the lamina propria. In the respiratory mucosa, ciliated epit helial cells, as well as serous gland acinar cells and vascular endoth elial cells in the lamina propria, were immunoreactive for this isozym e. An age-related decrement in the intensity and extent of immunoreact ivity within these cells was noted in nasal tissue from patients 60 ye ars of age and over when compared with that of patients under 60 years of age. These results identify sites of xenobiotic metabolism or acti vation in human nasal mucosa.