title: Cellular localization of 5α-reductase in the rat cerebellum.
abstract: The enzyme 5α-reductase catalyzes the transformation of progesterone, testosterone, and deoxycorticosterone into 5α-reduced metabolites, which are recognized as neurosteroids in the brain with variable potential neuroactivity. Two isoforms of 5α-reductase were identified in rodents, and, of these, 5α-reductase type 1 (5α-R1) is abundantly expressed in the brain. To understand the multiple influences of neurosteroids in the central nervous system, we need to know their region-specific synthesis. The present study reports the detailed localization of 5α-R1 in the adult rat cerebellum. The occurrence of 5α-R1 was detected by reverse transcription-polymerase chain reaction. The enzyme activity was also detected by thin layer chromatography. Immunocytochemistry showed 5α-R1 immunoreactive cells in all cerebellar layers. Multiple immunolabeling revealed that 5α-R1 was mainly localized in glia, such as astrocytes and oligodendrocytes. The most intense immunoreactivity for 5α-R1 was found in Bergmann glia, and the processes of these glia were associated with dendrites of both Purkinje cells and interneurons in the molecular layer. The 5α-R1 in the cerebellum was expressed consistently throughout different ages and sexes, in both gonadectomized and hypophysectomized rats. Thus, 5α-R1 may contribute to the formation and maintenance of the cerebellar neurons through 5α-reduced metabolites, which are synthesized through a complex interaction between neurons and glia.
authors.affiliation: Department of Anatomy, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan; Department of Anatomy and Cell Biology, Institute of Health Biosciences, The University of Tokushima, Graduate School, 3-18-15 Kuramoto, Tokushima, 770-8503, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Kiyokage
authors.affiliation: Department of Anatomy, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama, 701-0192, Japan; Department of Anatomy and Cell Biology, Institute of Health Biosciences, The University of Tokushima, Graduate School, 3-18-15 Kuramoto, Tokushima, 770-8503, Japan. Electronic address: toida@med.kawasaki-m.ac.jp.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Toida
authors.affiliation: Department of Nutritional Science, Okayama Prefectural University, 111 Kuboki, Soja, Okayama, 719-1197, Japan; Department of Anatomy and Cell Biology, Institute of Health Biosciences, The University of Tokushima, Graduate School, 3-18-15 Kuramoto, Tokushima, 770-8503, Japan.
authors.forename: Toshiko
authors.initials: T
authors.lastname: Suzuki-Yamamoto
authors.affiliation: Department of Anatomy and Cell Biology, Institute of Health Biosciences, The University of Tokushima, Graduate School, 3-18-15 Kuramoto, Tokushima, 770-8503, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Ishimura
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D002531:Cerebellum / Q000201:enzymology*; D042944:Cholestenone 5 alpha-Reductase / Q000032:analysis / Q000096:biosynthesis*; D005260:Female; D007150:Immunohistochemistry; D007395:Interneurons / Q000201:enzymology; D008297:Male; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009457:Neuroglia / Q000201:enzymology; D011689:Purkinje Cells / Q000201:enzymology; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D042944:Cholestenone 5 alpha-Reductase
keywords: 5α-reductase type 1; Astrocytes; Bergmann glia; Cerebellum; Neurosteroids; Oligodendrocytes