Localization of 3 beta-hydroxysteroid dehydrogenase in rat brain as studied by in situ hybridization.
Recent evidence suggests that brain cells can synthesize steroids de novo. The steroidogenic enzyme 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) gene family of enzymes is involved in the biosynthesis of all classes of active steroids. In the present study, we have used in situ hybridization performed with a 35S-labeled cDNA-encoding rat type I 3 beta-HSD to localize the expression of member(s) of this gene family in the adult rat brain. A specific hybridization signal could only be detected in a restricted area of the medulla ventrally and laterally bordering the fourth ventricle. This area contains the nucleus propositus hypoglossi as well as some vestibular nuclei: the nucleus vestibularis medialis, the nucleus vestibularis lateralis, and the nucleus vestibularis spinalis. At high resolution, the silver grains representing a hybridization signal were detected exclusively in neurons. The present data strongly suggest that a restricted population of neurons might be involved in steroid biosynthesis in the adult rat brain. The role of the member(s) of the rat 3 beta-HSD family in the nuclei of two cranial nerves remains to be investigated.
Dupont
E
E
MRC Group in Molecular Endocrinology, CHUL Research Center, Quebec, Canada.
Simard
J
J
Luu-The
V
V
Labrie
F
F
Pelletier
G
G
D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000201:enzymology* / Q000648:ultrastructure; D005260:Female; D017403:In Situ Hybridization; D008297:Male; D008854:Microscopy, Electron; D051381:Rats; D014018:Tissue Distribution
D015096:3-Hydroxysteroid Dehydrogenases