LOCALIZATION OF 11-BETA-HYDROXYSTEROID DEHYDROGENASE - SPECIFIC PROTECTOR OF THE MINERALOCORTICOID RECEPTOR IN MAMMALIAN OLFACTORY MUCOSA

The enzyme 11 beta-hydroxysteroid dehydrogenase (11 beta HSD) plays a major role in the protection of the mineralocorticoid (type I) recepto r. The cellular mechanism of aldosterone selectivity relies on the coe xpression of mineralocorticoid receptors and 11 beta HSD in the same c ells. In the current study, 11 beta HSD activity was localized in the mammalian olfactory mucosa by a histochemical technique which links st eroid metabolism with the deposition of formazan. The histochemical re action results from oxidation of the synthetic substrate 11 beta-hydro xyandrostenedione and is dependent on nicotine-adenine dinucleotide (N AD). This demonstrates the presence of a dehydrogenase activity separa te from the nicotineamide-adenine dinucleotide phosphate (NADP)-depend ent 11 beta HSD. In the olfactory mucosa, the presence of NAD-dependen t 11 beta HSD activity is localized to the sustentacular cells and aci nar cells of Bowman's glands. No definite NAD-dependent activity was d emonstrated in the olfactory receptor neurons. These data suggest that mineralocorticoid receptors present in acinar cells and sustentacular cells are aldosterone selective.