Note

Gas chromatographic determination of hypotaurine

A method for the determination of urinary hypotaurine and taurine for the purpose of studying hypotaurine—taurine status in mammals is described. Hypotaurine and taurine were converted into 4-dimethylaminoazobenzene-4′-sulfonyl (dabsyl) derivatives under conditions minimizing hypotaurine oxidation. The dabsylhypotaurine and dabsyltaurine formed were determined by reversed-phase HPLC. Average excretions of taurine and hypotaurine in rat urine were 270.5 and 2.5 μmol/kg body mass per day, respectively. After intraperitoneal injection of 5 mmol of l-cysteine/kg body mass, the increased excretions of taurine and hypotaurine corresponded to 22.1 and 2.5%, respectively, of l-cysteine administered, indicating that hypotaurine production exceeded the capacity of hypotaurine oxidation in vivo.