3α-hydroxy-5α-pregnan-20-one is the only active anesthetic steroid in anesthetized mouse brain

Abstract It was demonstrated that the anesthetic steroid 3α-hydroxy-5α-pregnan-20-one mediates the loss of the righting response (LRR) in mice, in contrast to its metabolites, which are forced in vivo. To reach these conclusions, it was necessary to quantitate levels for 3α-hydroxy-5α-pregnan-20-one and its metabolites at the time of LRR. Methods were used that blocked the production of essentially all of the metabolites. Chromatography of brain extracts by thin-layer chromatography and high-performance liquid chromatography after anesthesia with 3α-hydroxy-5α-[ 3 H]pregnan-20-obe showed only a single peak that corresponded to 3α-hydroxy-5α-[ 3 H]pregnan-20-one. (Steroids 58: 112–114, 1993)