title: Metabolism of terephthalic acid and its effects on CYP4B1 induction.
abstract: OBJECTIVE
  To investgate the metabolism of terephthalic acid (TPA) in rats and its mechanism. Methods Metabolism was evaluated by incubating sodium terephthalate (NaTPA) with rat normal liver microsomes, or with microsomes pretreated by phenobarbital sodium, or with 3-methycholanthrene, or with diet control following a NADPH-generating system. The determination was performed by high performance liquid chromatography (HPLC), and the mutagenic activation was analyzed by umu tester strain Salmonella typhimurium NM2009. Expression of CYP4B1 mRNA was detected by RT-PCR. Results The amount of NaTPA (12.5-200 micromol x L(-1)) detected by HPLC did not decrease in microsomes induced by NADPH-generating system. Incubation of TPA (0.025-0.1 mmol x L(-1)) with induced or noninduced liver microsomes in an NM2009 umu response system did not show any mutagenic activation. TPA exposure increased the expression of CYP4B 1 mRNA in rat liver, kidney, and bladder.
  
  
  CONCLUSIONS
  Lack of metabolism of TPA in liver and negative genotoxic data from NM2009 study are consistent with other previous short-term tests, suggesting that the carcinogenesis in TPA feeding animals is not directly interfered with TPA itself and/or its metabolites.
authors: Institute of Toxicology, Nanjing Medical University, 140 Hanzhong Road, Nanjing 210029, Jiangsu, China. daiguidong@163.com
authors: Gui-Dong
authors: GD
authors: Dai
authors: Lun-Biao
authors: LB
authors: Cui
authors: Ling
authors: L
authors: Song
authors: Ren-Zhen
authors: RZ
authors: Zhao
authors: Jian-Feng
authors: JF
authors: Chen
authors: Yu-Bang
authors: YB
authors: Wang
authors: Hebron C
authors: HC
authors: Chang
authors: Xin-Ru
authors: XR
authors: Wang