title: Room air versus carbon dioxide pneumoperitoneum: effects on oxidative state, apoptosis and histology of splanchnic organs.
abstract: BACKGROUND
  Although CO2 is the insufflation gas of choice in laparoscopic procedures, room air is usually used in natural orifice transluminal endoscopic surgery. The aim of the present study was to compare the safety of room air versus CO2 pneumoperitoneum in terms of their effect on the oxidative state, apoptosis and tissue injury of splanchnic organs.
  
  
  METHODS
  Eighteen Wistar rats were assigned to three groups (n = 6 per group) and were subjected to 8 mm Hg room air (group Pne-Air) or CO2 pneumoperitoneum (group Pne-CO2) or sham operation for 60 min. Forty-five minutes postdeflation, tissue samples were excised from the liver, stomach, ileum and kidneys for reduced glutathione-to-glutathione disulfide (GSH/GSSG) ratio, caspase-8 and caspase-3 and hypoxia-inducible factor-1α (HIF-1α) immunohistochemical assessment and histopathologic examination.
  
  
  RESULTS
  GSH/GSSG ratio substantially declined in both pneumoperitoneum groups. No change was noted in HIF-1α expression. Mild upregulation of caspase-8 and caspase-3 was noted in both pneumoperitoneum groups being less pronounced in group Pne-Air. Histopathologic score was increased in all organs studied, but the stomach, in both pneumoperitoneum groups.
  
  
  CONCLUSIONS
  Pneumoperitoneum established by either room air or CO2 induced substantial oxidative stress, mild apoptosis and mild tissue injury in splanchnic organs. While air pneumoperitoneum conferred a less pronounced apoptotic effect, the oxidative state and histopathologic profile of splanchnic organs did not differ between insufflation gases.
authors.affiliation: Laboratory of Experimental Surgery and Surgical Research, School of Medicine, Democritus University of Thrace, University Hospital of Alexandroupolis, Dragana, 68100, Alexandroupolis, Greece. pipsil@med.duth.gr.
authors.forename: Petros
authors.initials: P
authors.lastname: Ypsilantis
authors.affiliation: Laboratory of Histology and Embryology, School of Medicine, Democritus University of Thrace, Alexandroupolis, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Lambropoulou
authors.affiliation: Laboratory of Biochemistry, School of Medicine, Democritus University of Thrace, Alexandroupolis, Greece.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Tentes
authors.affiliation: Laboratory of Experimental Surgery and Surgical Research, School of Medicine, Democritus University of Thrace, University Hospital of Alexandroupolis, Dragana, 68100, Alexandroupolis, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Chryssidou
authors.affiliation: Laboratory of Experimental Surgery and Surgical Research, School of Medicine, Democritus University of Thrace, University Hospital of Alexandroupolis, Dragana, 68100, Alexandroupolis, Greece.
authors.forename: Themistoklis
authors.initials: T
authors.lastname: Georgantas
authors.affiliation: Laboratory of Experimental Surgery and Surgical Research, School of Medicine, Democritus University of Thrace, University Hospital of Alexandroupolis, Dragana, 68100, Alexandroupolis, Greece.
authors.forename: Constantinos
authors.initials: C
authors.lastname: Simopoulos
mesh_terms: D000388:Air; D000818:Animals; D017209:Apoptosis; D002245:Carbon Dioxide / Q000008:administration & dosage*; D004195:Disease Models, Animal; D007668:Kidney / Q000378:metabolism / Q000473:pathology*; D010535:Laparoscopy / Q000379:methods*; D008099:Liver / Q000378:metabolism / Q000473:pathology*; D008297:Male; D018384:Oxidative Stress; D011028:Pneumoperitoneum, Artificial / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D002245:Carbon Dioxide
keywords: Apoptosis; Carbon dioxide; Oxidative stress; Pneumoperitoneum; Room air