Sex steroid levels in corresponding cerebrospinal fluid and serum samples quantified by mass spectrometry in men

This study validated a highly sensitive gas chromatography–tandem mass spectrometry (GC-MS/MS) assay to quantify sex steroid hormones in cerebrospinal fluid (CSF) and serum samples from 47 men. The results showed that dehydroepiandrosterone (DHEA) was the predominant sex steroid in CSF, followed by androstenedione and testosterone, while dihydrotestosterone (DHT), estradiol (E2), and estrone (E1) were present at lower levels, and progesterone was generally undetectable. Strong correlations were found between CSF and serum levels for all sex steroids except E2. The study suggests that testosterone in CSF originates from circulating testosterone, DHT results from local conversion of testosterone, and E2 is derived from local conversion of androstenedione in the CNS. This assay provides a new tool for exploring the role of sex steroids in the human central nervous system.