Labile testosterone conjugate in human urine: further evidence

The origin of unconjugated testosterone released in human urine on storage and by dilute sulphuric acid treatment has been studied further. Various extraction procedures of urine have been employed and a new methodology involving anion exchange followed by acid hydrolysis and radioimmunoassay of the released unconjugated testosterone. Results indicate that human urine contains a very labile conjugate of testosterone and 5 alpha-dihydrotestosterone with polar solubility properties and a negative charge.