Studies on Neurosteroids X. Detemination of Pregnenolone and Dehydroepiandrosterone in Rat Brains Using Gas Chromatography-Mass Spectrometry-Mass Spectrometry

摘要

An assay method for rpegnenolone and dehdyroepiandrosterone in rate brains is developed using gas chromatography (GC)-electron ionization-mass spectrometry (MS)-MS. The extract of the rat brain homogenate containing deuterated internal standard with organic solvent is purified by silica gel minicolumn chromatography. The obtained fraction is derivatized into methyloxime, treatd with dimethylisopropylsilylimidazole, and then subjected to GC-MS-MS. The method is applied to the determination of these steroids in the gray matter and olfactory bulbs of rat brains, which are divided into control and acute stressed specimens. Although pregnenolone in both regions of the rat brains increases more than three times after stress, dehydroepiandrosterone in both regions is not so clearly influenced by stress.