title: Effects of simulated carbon dioxide and helium peumoperitoneum on proliferation and apoptosis of gastric cancer cells.
abstract: OBJECTIVE
  To investigate the effects of carbon dioxide (CO(2)) and helium insufflation administered at different pressures on the growth and apoptosis of cultured human gastric cancer cells.
  
  
  METHODS
  The gastric cancer cells MKN-45 were exposed to a CO(2) and helium environment maintained at different pressures (0, 5, 10 and 15 mmHg). The cells were exposed to simulated pneumoperitoneum environment for 4 h, and pH of the culture media was measured after it was moved to normal conditions for 0, 2, 4, 6 and 8 h. Proliferation viability of MKN-45 was examined by 3-[4,5Dimethylthiazol-2-yl],5-diphenyltetrazolium bromide or triazolyl blue (MTT) assay after it was moved to normal conditions. Apoptotic ratio was measured by Annexin V-FITC/PI double labelled staining.
  
  
  RESULTS
  The pH of media was acid and recovered to normal after 4 h in the CO(2) group while it was basic in the helium group. There was no difference between CO(2) groups (under 10 mmHg ) and control group (P > 0.05) in the proliferative viability of the cells. The cultured cells exposed to 15 mmHg CO(2) environment grew more slowly than control group from 4 to 7 d (P < 0.01 ) while there was no difference from 1 to 3 d (P > 0.05). The proliferative viability in helium group was not obviously different from the control group (P > 0.05). The apoptotic ratio of the cultured cells was markedly higher than that of the control group (P < 0.01) at 10 and 15 mmHg CO(2) insufflation pressure. In helium group, the apoptotic ratio was not obviously different from the control group (P > 0.05).
  
  
  CONCLUSIONS
  There is no obvious effect in the proliferation and apoptosis of MKN-45 cells under 10 mmHg CO(2) insufflation pressure and helium in any pressure. Fifteen mmHg CO(2) insufflation pressure can inhibit the proliferation of the cells and improve apoptosis.
authors.affiliation: Department of General Surgery, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
authors.forename: Ying-Xue
authors.initials: YX
authors.lastname: Hao
authors.forename: Hua
authors.initials: H
authors.lastname: Zhong
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.forename: Dong-Zu
authors.initials: DZ
authors.lastname: Zeng
authors.forename: Yan
authors.initials: Y
authors.lastname: Shi
authors.forename: Bo
authors.initials: B
authors.lastname: Tang
authors.forename: Pei-Wu
authors.initials: PW
authors.lastname: Yu
mesh_terms: D017304:Annexin A5 / Q000494:pharmacology; D017209:Apoptosis; D002245:Carbon Dioxide / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D005740:Gases; D006371:Helium / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011028:Pneumoperitoneum, Artificial; D011312:Pressure; D013274:Stomach Neoplasms / Q000473:pathology*; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D013997:Time Factors
chemical_list: D017304:Annexin A5; D005740:Gases; D013778:Tetrazolium Salts; D013844:Thiazoles; D002245:Carbon Dioxide; D006371:Helium; C022616:thiazolyl blue