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ID 34762
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creator
Higo, Shimpei
Hojo, Yasushi
Ishii, Hirotaka
Komatsuzaki, Yoshimasa
Ooishi, Yuuki
Murakami, Gen
Mukai, Hideo
Nakahara, Daiichiro
Barron, Anna
Kimoto, Tetsuya
Kawato, Suguru
NDC
Medical sciences
abstract
Background: Brain synthesis of steroids including sex-steroids is attracting much attention. The endogenous synthesis of corticosteroids in the hippocampus, however, has been doubted because of the inability to detect deoxycorticosterone (DOC) synthase, cytochrome P450(c21).

Methodology/Principal Findings: The expression of P450(c21) was demonstrated using mRNA analysis and immmunogold electron microscopic analysis in the adult male rat hippocampus. DOC production from progesterone (PROG) was demonstrated by metabolism analysis of 3H-steroids. All the enzymes required for corticosteroid synthesis including P450(c21), P450(2D4), P450(11b1) and 3b-hydroxysteroid dehydrogenase (3b-HSD) were localized in the hippocampal principal neurons as shown via in situ hybridization and immunoelectron microscopic analysis. Accurate corticosteroid concentrations in rat hippocampus were determined by liquid chromatography-tandem mass spectrometry. In adrenalectomized rats, net hippocampus-synthesized corticosterone (CORT) and DOC were determined to 6.9 and 5.8 nM, respectively. Enhanced spinogenesis was observed in the hippocampus following application of low nanomolar (10 nM) doses of CORT for 1 h.

Conclusions/Significance: These results imply the complete pathway of corticosteroid synthesis of ‘pregnenolone RPROGRDOCRCORT' in the hippocampal neurons. Both P450(c21) and P450(2D4) can catalyze conversion of PROG to DOC. The low nanomolar level of CORT synthesized in hippocampal neurons may play a role in modulation of synaptic plasticity, in contrast to the stress effects by micromolar CORT from adrenal glands.
journal title
PLoS ONE
volume
Volume 6
issue
Issue 7
start page
e21631
date of issued
2011
publisher
Public Library of Science
issn
1932-6203
publisher doi
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
publisher
rights
(c) 2011 Higo et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
relation url
department
Graduate School of Integrated Arts and Sciences