Brand A, Leibfritz D, Hamprecht B, Dringen R
Institut für Organische Chemie, Universität Bremen, Germany.
J Neurochem. 1998 Aug;71(2):827-32. doi: 10.1046/j.1471-4159.1998.71020827.x.
The synthesis of hypotaurine and taurine was investigated in astroglia-rich primary cultures obtained from brains of neonatal Wistar rats using 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. Cell extracts of astroglial cultures analyzed by 1H 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 13C 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.
利用氢核磁共振（1H NMR）光谱和碳-13核磁共振（13C NMR）光谱，对从新生Wistar大鼠大脑中获取的富含星形胶质细胞的原代培养物中的亚牛磺酸和牛磺酸的合成进行了研究。通过1H NMR光谱分析的星形胶质细胞培养物的细胞提取物显示出亚牛磺酸的显著信号。为了确定半胱氨酸是星形胶质细胞中亚牛磺酸和牛磺酸合成的前体，原代培养物与[3-(13)C]半胱氨酸一起孵育24或72小时。然后用13C NMR光谱分析细胞提取物和孵育培养基。在细胞提取物中鉴定出标记的亚牛磺酸、牛磺酸、谷胱甘肽和乳酸。在72小时内，细胞内总亚牛磺酸的35.0%和牛磺酸的22.5%是由[3-(13)C]半胱氨酸新合成的。孵育培养基中存在[1-(13)C]亚牛磺酸和[1-(13)C]牛磺酸，证明了半胱氨酸代谢产物释放到培养基中。少量的[3-(13)C]半胱氨酸用于星形胶质细胞中谷胱甘肽的合成，或代谢为[3-(13)C]乳酸，在细胞提取物和培养基中均有发现。这些结果表明，亚牛磺酸和牛磺酸的形成是星形胶质细胞中半胱氨酸代谢的主要途径。
