Initial Intraorgan Formation of Mercapturic Acid.
作者:Kazumi SANO、Yoji IKEGAMI、Takashi UESUGI
DOI:10.1248/bpb.24.1324
日期:——
The disposition of S-benzyl-glutathione (BSG) in male Wistar rats was evaluated by the HPLC method to examine whether the kidney and liver contributed independently to the biosynthesis of S-benzyl-N-acetylcysteine (BNAc), a mercapturic acid (Chart 1). After intravenous injection, BSG was rapidly transported in both the kidney and the liver at a ratio of about 7:3. Simultaneously, a large amount of BNAc was found in both the kidney and the liver. In the kidney, S-benzyl-cysteine (BCys) reached a maximum concentration (Cmax) at 2 min after BSG injection, whereas BNAc reached Cmax within 3 to 5 min. The generation of BNAc was also observed in the liver. While renal BNAc reached Cmax within 3 to 5 min, hepatic BNAc reached Cmax around 5 min after BSG injection. Moreover, the elimination half-life of the BNAc after intravenous injection of the BSG was equivalent to that observed after intravenous injection of the BNAc itself. These results demonstrate that the kidney contributes to the initial intraorgan generation of BNAc and that this mercapturic acid is also synthesized in the liver and preferentially excreted into urine.
采用高效液相色谱法评估雄性Wistar大鼠体内S-苄基谷胱甘肽(BSG)的代谢情况,以检验肾脏和肝脏是否独立参与合成S-苄基-N-乙酰半胱氨酸(BNAc)(图1:硫醚氨酸)。静脉注射后,BSG在肾脏和肝脏中的转运速率约为7:3。同时,在肾脏和肝脏中发现了大量的BNAc。在肾脏中,S-苄基-半胱氨酸(BCys)在BSG注射后2分钟达到最大浓度(Cmax),而BNAc在3至5分钟内达到Cmax。BNAc的生成也在肝脏中得到了观察。虽然肾脏中的BNAc在3至5分钟内达到Cmax,但肝脏中的BNAc在BSG注射后约5分钟达到Cmax。此外,静脉注射BSG后BNAc的消除半衰期与静脉注射BNAc本身的观察结果相当。这些结果表明,肾脏对BNAc的初始体内生成有贡献,这种硫醚氨酸也在肝脏中合成并优先排入尿液。