An LC-APCI+-MS/MS-based method for determining the concentration of neurosteroids in the brain of male mice with different gut microbiota

Abstract

BackgroundAlthough the interaction between the gut microbiota and central nervous system (CNS) is well-known, the effects of gut microbiota on different brain regions remain obscure. New methodIn present study, we developed a simple and sensitive high-performance liquid chromatography-tandem mass spectrometry with atmospheric pressure chemical ionization in positive mode (LC-APCI+-MS/MS) for simultaneous detection of 12 analytes in the rodent’ brain with different housing conditions ResultsThe results showed that male mice in XZ group had significantly higher brain levels of dehydroepiandrosterone (DHEA), androstenedione (A4), testosterone (T), progesterone (P), corticosterone (CORT), aldosterone (ALD) and 11-dehydrocorticosterone (11-DHC) than those in SPF group. CORT level was higher in the left prefrontal cortex, whereas ALD and 11-DHC levels were higher in the left hypothalamus than in the right symmetrical areas in both groups. DHEA and CORT levels were highest in the striatum than in the prefrontal cortex, hippocampus, hypothalamus, regardless of the region and group (XZ and SPF). Comparison with existing methodsThese results demonstrated that the method developed in this study provides, for the first time, direct quantitation of neurosteroids in male mice brain. ConclusionsDHEA levels showed a left-lateralized pattern in the hippocampus and hypothalamus. Mice in the XZ group showed significantly elevated levels of CORT and/or its metabolites, ALD and 11-DHC in brain than mice in the SPF group. Insanitation living conditions increased more diverse gut microbiota.