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Metabolism of Cysteine in Astroglial Cells: Synthesis of Hypotaurine and Taurine
Author(s) -
Brand Annette,
Leibfritz Dieter,
Hamprecht Bernd,
Dringen Ralf
Publication year - 1998
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1998.71020827.x
Subject(s) - hypotaurine , taurine , cysteine , biochemistry , glutathione , metabolism , cysteine metabolism , chemistry , biology , amino acid , enzyme
The synthesis of hypotaurine and taurine was investigated in astroglia‐rich primary cultures obtained from brains of neonatal Wistar rats using 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy. Cell extracts of astroglial cultures analyzed by 1 H NMR spectroscopy show prominent signals of hypotaurine. To identify cysteine as precursor for hypotaurine and taurine synthesis in astroglial cells, primary cultures were incubated with [3‐ 13 C]cysteine for 24 or 72 h. Cell extracts and incubation media were then analyzed with 13 C NMR spectroscopy. Labeled hypotaurine, taurine, glutathione, and lactate were identified in the cell extracts. Within 72 h, 35.0% of the total intracellular hypotaurine and 22.5% of taurine were newly synthesized from [3‐ 13 C]cysteine. The presence of [1‐ 13 C]hypotaurine and [1‐ 13 C]taurine in the incubation medium proves the release of those products of cysteine metabolism into the medium. Minor amounts of the [3‐ 13 C]cysteine were used for the synthesis of glutathione in astroglial cells or metabolized to [3‐ 13 C]lactate, which was found in cell extracts and media. These results indicate that the formation of hypotaurine and taurine is a major pathway of cysteine metabolism in astroglial cells.