title: Effects of pneumoperitoneal gases and pressures on transitional cell carcinoma adhesion, growth, apoptosis and necrosis: an in vitro study.
abstract: OBJECTIVE
  We studied the effects of insufflation gas and pressure on the adhesion, growth, apoptosis and necrosis of transitional cell carcinoma (TCC) in an in vitro model.
  
  
  METHODS
  Tumor adhesion and cell growth of AY-27 rat TCC was measured after 3-hour incubation with CO2, N2 and He insufflation at different pressures (0, 10 and 15 mm Hg) in vitro. The effects of these gases on the rate of tumor cell apoptosis and necrosis were compared.
  
  
  RESULTS
  In vitro the tumor adhesion rate was lowest with CO2 and highest with N2. Higher gas pressures resulted in decreased adhesion rates for CO2 and He but increased adhesion rates for N2. N2 enhanced tumor cell proliferation at all pressures studied. He and CO2 resulted in an initial increase in cell proliferation in the first 24 hours, followed by a decrease in tumor growth. Extracellular medium turned acidic in CO2 (pH 6.27 to 6.39) but basic in N2 and He (pH 8.39 to 8.84). At all insufflation pressures studied apoptosis and necrosis rates were increased in the first 24 hours, followed by a decrease for CO2 and N2. He resulted in increasing apoptosis and necrosis throughout the study period.
  
  
  CONCLUSIONS
  The type of gas and insufflation pressure affects cell adhesion and tumor growth. There was a significant increase in tumor adhesion and proliferation with N2 insufflation compared with CO2 and He at 0 to 15 mm Hg pressures. CO2 demonstrated the greatest decrease in TCC adhesion and proliferation at 15 mm Hg pressure. Apoptosis and necrosis were highest for He compared with the other gases.
authors.affiliation: Department of Urology, Long Island Jewish Medical Center, New Hyde Park, New York 11040-1496, USA.
authors.forename: Beng Jit
authors.initials: BJ
authors.lastname: Tan
authors.forename: Jun Sy
authors.initials: JS
authors.lastname: Dy
authors.forename: Pui Yan
authors.initials: PY
authors.lastname: Chiu
authors.forename: Shiva A
authors.initials: SA
authors.lastname: Mathura
authors.forename: Michael C
authors.initials: MC
authors.lastname: Ost
authors.forename: Leslie
authors.initials: L
authors.lastname: Kushner
authors.forename: Arthur D
authors.initials: AD
authors.lastname: Smith
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Lee
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002245:Carbon Dioxide; D002295:Carcinoma, Transitional Cell / Q000503:physiopathology*; D002448:Cell Adhesion / Q000187:drug effects; D049109:Cell Proliferation; D005740:Gases / Q000494:pharmacology*; D006371:Helium; D007327:Insufflation; D009336:Necrosis; D009584:Nitrogen; D011028:Pneumoperitoneum, Artificial; D011312:Pressure; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000503:physiopathology*
chemical_list: D005740:Gases; D002245:Carbon Dioxide; D006371:Helium; D009584:Nitrogen