title: Esophageal and gastric smooth muscle activity after carbon dioxide pneumoperitoneum.
abstract: BACKGROUND
  The metabolic changes associated with carbon dioxide (CO(2)) pneumoperitoneum include metabolic acidosis and lowered intra-abdominal pH values. An experimental study was performed to evaluate the effect of CO(2) pneumoperitoneum on esophageal and gastric smooth muscle sensitivity in response to several agonists.
  
  
  METHODS
  Wistar albino rats, weighing 200-250 g, were allocated into three groups. After anesthetization with ketamine hydrochloride and xylazine, abdominal esophagus, gastroesophageal junction, and gastric fundus were removed via median laparotomy in the control group. In the oxygen (O(2)) group, a 16G catheter was inserted into the abdomen above the umbilicus and insufflated with 95% O(2) and 5% CO(2) with a pressure of 10 mm Hg. In the CO(2) group, CO(2) was insufflated at the same pressure within the same time and the tissues were removed at the end of a 60 min period of pneumoperitoneum. Abdominal esophageal segment (n:6), gastroesophageal junction (n:6) and gastric fundus (n:12) were suspended under 0.5 to 2 g resting tension in Tyrode solution in organ baths. Contraction responses were obtained by carbachol and serotonin and relaxation responses were evaluated by isoproterenol in each group. All the responses were compared by nonparametric Kruskal Wallis test.
  
  
  RESULTS
  Carbachol and serotonin induced contractile responses of abdominal segments, gastroesophageal junction, and gastric fundus showed no difference between the control, O(2), and CO(2) groups (P > 0.05). Isoproterenol relaxation responses of the three groups were also not statistically different from each other (P > 0.05).
  
  
  CONCLUSIONS
  CO(2) pneumoperitoneum of 60 min has no influence on esophageal and gastric smooth muscle responses to different agonists in rats.
authors.affiliation: Department of Pediatric Surgery, Kirikkale University, Faculty of Medicine Kirikkale, Turkey. tutku@sanalofis.net
authors.forename: Tutku
authors.initials: T
authors.lastname: Soyer
authors.forename: Zuhal
authors.initials: Z
authors.lastname: Aktuna
authors.forename: Tolga
authors.initials: T
authors.lastname: Reşat Aydos
authors.forename: Gökhan
authors.initials: G
authors.lastname: Osmanoğlu
authors.forename: Oğuzhan
authors.initials: O
authors.lastname: Korkut
authors.forename: Hülya
authors.initials: H
authors.lastname: Akman
authors.forename: Murat
authors.initials: M
authors.lastname: Cakmak
mesh_terms: D000005:Abdomen / Q000503:physiopathology; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002245:Carbon Dioxide / Q000494:pharmacology; D004947:Esophagus / Q000187:drug effects / Q000503:physiopathology*; D007545:Isoproterenol / Q000494:pharmacology; D007813:Laparotomy / Q000379:methods; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000503:physiopathology*; D011027:Pneumoperitoneum / Q000139:chemically induced / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000494:pharmacology; D013270:Stomach / Q000187:drug effects / Q000503:physiopathology*
chemical_list: D002245:Carbon Dioxide; D012701:Serotonin; D002217:Carbachol; D007545:Isoproterenol