title: In vitro effect of pantoprazole on lower esophageal sphincter tone in rats.
abstract: OBJECTIVE
  To investigate the in vitro effects of pantoprazole on rat lower esophageal sphincter (LES) tone.
  
  
  METHODS
  Rats weighing 250-300 g, provided by the Yeditepe University Experimental Research Center (YÜDETAM), were used throughout the study. They were anesthetized before decapitation. LES tissues whose mucosal lining were removed were placed in a standard 30-mL organ bath with a modified Krebs solution and continuously aerated with 95% oxygen-5% carbon dioxide gas mixture and kept at room temperature. The tissues were allowed to stabilize for 60 min. Subsequently, the contractile response to 10(-6) mol/L carbachol was obtained. Different concentrations of freshly prepared pantoprazole were added directly to the tissue bath to generate cumulative concentrations of 5 × 10(-6) mol/L, 5 × 10(-5) mol/L, and 1.5 × 10(-4) mol/L. Activities were recorded on an online computer via a 4-channel transducer data acquisition system using the software BSL PRO v 3.7, which also analyzed the data.
  
  
  RESULTS
  Pantoprazole at 5 × 10(-6) mol/L caused a small, but statistically insignificant, relaxation in the carbachol-contracted LES (2.23% vs 3.95%). The 5 × 10(-5) mol/L concentration, however, caused a significant relaxation of 10.47% compared with the control. 1.5 × 10(-4) mol/L concentration of pantoprazol caused a 19.89% relaxation in the carbachol contracted LES (P < 0.001).
  
  
  CONCLUSIONS
  This is the first study to demonstrate that pantoprazole has a relaxing effect in isolated LESs. These results might have significant clinical implications for the subset of patients using proton pump inhibitors who do not receive full symptomatic alleviation from gastroesophageal reflux disease.
authors.affiliation: Department of Gastrointestinal Surgery, Kartal Kosuyolu Education and Research Hospital, Cevizli, Kartal, 34846 Istanbul, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Duman
authors.forename: Mahmut
authors.initials: M
authors.lastname: Ozer
authors.forename: Enver
authors.initials: E
authors.lastname: Reyhan
authors.forename: Yeliz
authors.initials: Y
authors.lastname: Demirci
authors.forename: Ali E
authors.initials: AE
authors.lastname: Atıcı
authors.forename: Tahsin
authors.initials: T
authors.lastname: Dalgıç
authors.forename: Erdal B
authors.initials: EB
authors.lastname: Bostancı
authors.forename: Ece
authors.initials: E
authors.lastname: Genç
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D018679:Cholinergic Agonists / Q000494:pharmacology; D049630:Esophageal Sphincter, Lower / Q000187:drug effects* / Q000502:physiology*; D005764:Gastroesophageal Reflux / Q000188:drug therapy; D006801:Humans; D009129:Muscle Tonus / Q000187:drug effects*; D000077402:Pantoprazole; D054328:Proton Pump Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D018679:Cholinergic Agonists; D054328:Proton Pump Inhibitors; D002217:Carbachol; D000077402:Pantoprazole