Excretion of bisphenol A-glucuronide into the small intestine and deconjugation in the cecum of the rat
Excretion of bisphenol A-glucuronide into the small intestine and deconjugation in the cecum of the rat
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DOI：
10.1016/s0304-4165(02)00418-x
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发表时间：
2002-11-14
影响因子：
3
通讯作者：
Yuasa, A
中科院分区：
文献类型：
--
作者：
Sakamoto, H;Yokota, H;Yuasa, A
环境雌激素双酚A （BPA）被认为是内分泌系统的调节剂，有报道称对动物生殖器官有不利影响。在大鼠中，双酚a在肝脏中通过udp -葡萄糖醛酸转移酶UGT2B1代谢为葡萄糖醛酸盐，并排泄到胆汁中。在本研究中，我们发现大部分排泄到小肠的双酚a -葡糖苷（BPA-GA）在盲肠内容物中被解结。BPA给药后，在小肠上部的内容物中发现BPA- ga（立即应该是15分钟），然后转移到小肠下部。然而，盲肠内容物中只发现了游离BPA，结肠内容物中游离BPA的含量较少，说明BPA在结肠中被重新吸收。从盲肠内容物中提取的提取物解共轭BPA-GA，其中含有最高的β -葡萄糖醛酸酶（β - gase）， Western blot分析中使用抗细菌β - gase抗体观察到。这些结果表明双酚a的肠肝循环，并表明双酚a的不良影响会随着反复接触而增强。(C) 2002 Elsevier Science b.v.版权所有
The environmental estrogen bisphenol A (BPA) is regarded as a modulator of endocrine systems and has been reported to have adverse effects on the reproductive organs of animals. In rats, BPA is metabolized to glucuronide by UDP-glucuronosyltransferase UGT2B1 in the liver and excreted into the bile. In the present study, we found that most of the bisphenol A-glucuronide (BPA-GA) excreted into the small intestine was deconjugated in the contents of the cecum. After BPA administration, BPA-GA was (immediately should be 15 min) found in the contents of the upper part of the small intestine, and then it moved to the lower part of the small intestine. However, only free BPA was found in the content of the cecum, and there was smaller amount of free BPA in the colon contents, indicating that BPA had been reabsorbed in the colon. BPA-GA was deconjugated by extract prepared from the cecum content which included highest beta-glucuronidase (beta-Gase) observed in Western blot analysis using antibodies against bacterial beta-Gase. These results indicate enterohepatic circulation of BPA and suggest that the adverse effects of BPA are enhanced by repeated exposure. (C) 2002 Elsevier Science B.V All rights reserved.