title: The biosynthesis of taurine fromN-acetyl-L-cysteine and other precursorsin vivo and in rat hepatocytes.
abstract: The synthesis of taurine fromN-acetylcysteine has been examined in ratsin vivo and in rat hepatocyte suspensionsin vitro. In ratsin vivo, administration ofN-acetylcysteine significantly increased urinary taurine (3 fold) 24h after dosing and liver glutathione levels. Liver taurine was not increased significantly. In hepatocytes incubated in the presence ofN-acetylcysteine, glutathione concentration increased to a maximum after 1 hour but the increase was not dependent on the concentration ofN-acetylcysteine. In contrast, after an initial lag phase, taurine synthesis increased in relation to the concentration ofN-acetylcysteine and continued for 3 hours. Glutathione synthesis seems to be preferential to taurine synthesis. Taurine synthesis from cysteine sulphinate was greater and from hypotaurine was greatest and maximal after 1 hour. Implications for the mechanism of protection byN-acetylcysteine are discussed.
authors.affiliation: Department of Toxicology, School of Pharmacy, University of London, 29/39 Brunswick Square, WC1N 1AX, London, UK.
authors.forename: C J
authors.initials: CJ
authors.lastname: Waterfield
authors.forename: J A
authors.initials: JA
authors.lastname: Timbrell