title: Induction of bladder lesion by terephthalic acid and its mechanism.
abstract: OBJECTIVE
  To provide more information for rational evaluation of potential risks of terephthalic acid (TPA), we studied the effects of TPA on rats' bladders in 90 days after TPA exposure.
  
  
  METHODS
  Sprague Dawley rats were subdivided into five groups, ingesting 0%, 0.04%, 0.2%, 1%, and 5% TPA respectively for a sub-chronic feeding study lasting for 90 days. Urine, serum and samples of brain, liver, lung, kidney, bladder, etc. were collected and analyzed.
  
  
  RESULTS
  TPA ingesting decreased the value of urinary pH, and increased the contents of Ca2+, Zn2+, Mg2+, Na+, K+ in urine. The volume of 24 h urine was significantly increased in male rats in the 1% and 5% TPA groups. Urinary white sediment was found in both sexes, and its formation in male rats seemed more susceptible than that in female rats. Alpha 2u-globulin (AUG) in serum and urine of male rats was markedly increased in a dose-dependent manner. Fifteen cases of hyperplasia (simple or atypical) were determined in the 5% TPA ingesting group, 14/52 in male rats and 1/23 in female rats. Among them 3 male rats had no stone or calculus. Those with either bladder stones or hyperplasia were accompanied with urinary white sediments.
  
  
  CONCLUSIONS
  White sediment accompanied with elevated urine AUG is the basis of TPA induced urolith formation, and is also associated with TPA induced bladder epithelial cell proliferation. It can act as an early biomarker for the potential toxic effect of TPA.
authors.affiliation: Institute of Toxicology, Nanjing Medical University, Jiangsu, China. daiguidong@163.com
authors.forename: Gui-Dong
authors.initials: GD
authors.lastname: Dai
authors.forename: Lun-Biao
authors.initials: LB
authors.lastname: Cui
authors.forename: Ling
authors.initials: L
authors.lastname: Song
authors.forename: Ren-Zhen
authors.initials: RZ
authors.lastname: Zhao
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Cheng
authors.forename: Mei-Xia
authors.initials: MX
authors.lastname: Liu
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Zhou
authors.forename: Hang
authors.initials: H
authors.lastname: Xiao
authors.forename: Xin-Ru
authors.initials: XR
authors.lastname: Wang
mesh_terms: D000510:Alpha-Globulins / Q000652:urine; D000818:Animals; D015415:Biomarkers / Q000652:urine; D005260:Female; D006965:Hyperplasia / Q000139:chemically induced*; D008297:Male; D010795:Phthalic Acids / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D001743:Urinary Bladder / Q000187:drug effects* / Q000473:pathology; D001744:Urinary Bladder Calculi / Q000139:chemically induced*
chemical_list: D000510:Alpha-Globulins; D015415:Biomarkers; D010795:Phthalic Acids; C013803:alpha 2u globulin; C011363:terephthalic acid