Studies on Neurosteroids XXIV: Determination of Neuroactive Androgens, Androsterone and 5α-Androstane-3α,17β-Diol, in Rat Brain and Serum Using Liquid Chromatography–Tandem Mass Spectrometry

The study developed and validated methods using liquid chromatography–tandem mass spectrometry to quantify neuroactive androgens, androsterone and 5α-androstane-3α,17β-diol, in rat brain and serum. The methods demonstrated high accuracy and reproducibility, with intra- and inter-assay relative standard deviations below 3.6% and accuracy values between 97.1% and 103.7%. The study found that most 5α-androstane-3α,17β-diol in the brain was derived from the periphery, while androsterone was both transported from the periphery and synthesized in the brain. Administration of finasteride, a 5α-reductase inhibitor, significantly reduced brain levels of both androgens and increased the brain level of androstenedione, the precursor of androsterone.