title: In vitro exposure to carbon dioxide induces oxidative stress in human peritoneal mesothelial cells.
abstract: BACKGROUND
  The objective of this study was to verify whether in vitro exposure of human peritoneal mesothelial cells to carbon dioxide (CO(2)) influences the levels of 8-isoprostaglandin F(2alpha) (8-iso-PGF(2alpha)), a marker of oxidative stress.
  
  
  METHODS
  Mesothelial cells were exposed to either: (i). 100% CO(2) for 4 h; (ii). 100% helium (an alternative gas with which to create hypoxic conditions) for 4 h; (iii). 100% CO(2) for 24 h; or (iv). standard conditions (control). After gas exposure, mesothelial cells were returned to standard conditions and harvested immediately (T(0)), and at 1-(T(1)) and 3 (T(3)) h afterwards. Cell viability and culture medium pH were monitored throughout the experiments. 8-iso-PGF(2alpha) was assayed by enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  Exposure to CO(2) decreased the culture medium pH whereas helium increased the pH. 8-iso-PGF(2alpha) levels in all treated groups were significantly higher than in the control group: in the 4 h CO(2) group at T(1); in the 24 h CO(2) group at T(0) and T(1); and in the 4 h helium group at T(0), T(1) and T(3). 8-iso-PGF(2alpha) levels following 4 h CO(2) exposure were significantly lower than after 24 h CO(2) exposure at T(1), and lower than following 4 h helium exposure at all time points.
  
  
  CONCLUSIONS
  Exposure to both CO(2) and helium induces oxidative stress in mesothelial cells. Hypoxia-reoxygenation may play a role in this process.
authors.affiliation: Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong SAR.
authors.forename: Angela M
authors.initials: AM
authors.lastname: Bentes de Souza
authors.forename: Chi Chiu
authors.initials: CC
authors.lastname: Wang
authors.forename: Ching Yan
authors.initials: CY
authors.lastname: Chu
authors.forename: Christine M
authors.initials: CM
authors.lastname: Briton-Jones
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Haines
authors.forename: Michael Scott
authors.initials: MS
authors.lastname: Rogers
mesh_terms: D000328:Adult; D002245:Carbon Dioxide / Q000494:pharmacology*; D002478:Cells, Cultured; D003470:Culture Media / Q000737:chemistry; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D005260:Female; D006371:Helium / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D018384:Oxidative Stress; D010537:Peritoneum / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*
chemical_list: D003470:Culture Media; D002245:Carbon Dioxide; D006371:Helium; C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost