title: Presence of Sex Steroid-Metabolizing Enzymes in the Olfactory Mucosa of Rats.
abstract: Although several lines of evidence have suggested that sex steroids influence olfaction, little is known about the cellular basis of steroid-metabolizing enzymes in the olfactory system. Thus, we aimed to examine gene expression and immunolocalization of four sex steroid-metabolizing enzymes in the olfactory mucosa (OM) of albino rats; steroid side chain-cleaving enzyme (P450scc), 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD-1), 17β-HSD type 2 (17β-HSD-2), and aromatase. P450scc is known to catalyze conversion from cholesterol to pregnenolone. 17β-HSD-1 catalyzes conversion from estrone to estradiol, and 17β-HSD-2 does the reverse. Aromatase catalyzes the conversion from testosterone to estradiol-17β. Messenger (m) RNAs of all four enzymes mentioned above were detected in the OM. Western blot analysis demonstrated that P450scc, 17β-HSD-1, and 17β-HSD-2 were detected in the OM. Immunoreactivity for these three enzymes was observed in sustentacular cells of the olfactory epithelium and acinar cells of Bowman's glands. Immunoelectron microscopy analysis demonstrated immunoreactivity for P450scc in mitochondria, and for 17β-HSD-1 and 17β-HSD-2 in the well-developed smooth endoplasmic reticulum and myeloid bodies of the sustentacular cells. The present study suggests that sustentacular cells and acinar cells of the Bowman's glands in the rat OM express at least three of the steroid-metabolizing enzymes, that is, P450scc 17β-HSD-1, and 17β-HSD-2, and de novo synthesis of estradiol takes place in the OM. Anat Rec, 300:402-414, 2017. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Laboratory of Anatomy and Celluler Biology Graduate School of Health Sciences, Kyorin University, Tokyo, Japan.|Department of Anatomy, Kawasaki Medical School, Okayama, Japan.
authors.forename: Sawa
authors.initials: S
authors.lastname: Horie
authors.affiliation: Department of Biomedical Laboratory Science Faculty of Health Sciences, Kyorin University, Tokyo, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Yamaki
authors.affiliation: Laboratory of Anatomy and Celluler Biology Graduate School of Health Sciences, Kyorin University, Tokyo, Japan.|Sakai Electron Microscopy Application Laboratory, Saitama, Japan.|Department of Physical Therapy Faculty of Social Work Studies, Josai International University, Chiba-ken, Japan.|Laboratory of Neuroscience Department of Physiology, Iwate Medical University School of Dentistry, Iwate, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Takami
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D000818:Animals; D001141:Aromatase / Q000378:metabolism*; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D009831:Olfactory Mucosa / Q000201:enzymology*; D051381:Rats
chemical_list: D015067:17-Hydroxysteroid Dehydrogenases; C044256:3 (or 17)-beta-hydroxysteroid dehydrogenase; D001141:Aromatase; D002786:Cholesterol Side-Chain Cleavage Enzyme
keywords: estradiol; immunoelectron microscopy; immunoreactivity; smooth endoplasmic reticulum; sustentacular cell