title: The effect of rabeprazole on LES tone in experimental rat model.
abstract: BACKGROUND
  Despite adequate treatment with proton pump inhibitors (PPIs), symptoms of gastroesophageal reflux disease (GERD) may remain persistent as well as Barrett's esophagus may emerge. It may be proposed that the relaxant effect of PPIs on the smooth muscles may lead to resistance of symptoms. The aim of this study is to investigate effects of rabeprazole on the lower esophageal sphincter (LES) pressure with a rat model.
  
  
  METHODS
  Sixteen rats were grouped as control and treatment groups. After obtaining LES tissues followed by a 60 min equilibration period for stabilization, contractile response to carbachol was obtained by application of single dose of carbachol to have a final concentration of 10(-6) M in the organ bath. After the contractions reached a plateau, concentration-response relationships for rabeprazole were obtained in a cumulative manner in the treatment group.
  
  
  RESULTS
  In the carbachol contracted LES preparations; 1.5 × 10(-6) and 1.5×10(-5) M of rabeprazole caused 6.08% and 11.34% relaxations respectively which were not statistically significant. However, mean integral relaxation value for 4.5 × 10(-5) M of rabeprazole was 17.34% and this relaxation was significant compared with controls.
  
  
  CONCLUSIONS
  In the present study, rabeprazole caused no direct significant change in LES tone in the therapeutic dose range applied to the organ bath. However, rabeprazole at the high dose caused a significant decrease in the LES tone.
authors.affiliation: Department of Gastrointestinal Surgery, Kartal Kosuyolu Training and Research Hospital, Istanbul, Turkey. drmustafaduman@hotmail.com
authors.forename: Mustafa
authors.initials: M
authors.lastname: Duman
authors.forename: Erdal
authors.initials: E
authors.lastname: Polat
authors.forename: Mahmut
authors.initials: M
authors.lastname: Ozer
authors.forename: Yeliz
authors.initials: Y
authors.lastname: Demirci
authors.forename: Necdet Fatih
authors.initials: NF
authors.lastname: Yasar
authors.forename: Cebrail
authors.initials: C
authors.lastname: Akyuz
authors.forename: Orhan
authors.initials: O
authors.lastname: Uzun
authors.forename: Kıvanc Derya
authors.initials: KD
authors.lastname: Peker
authors.forename: Ece
authors.initials: E
authors.lastname: Genc
authors.forename: Sinan
authors.initials: S
authors.lastname: Yol
mesh_terms: D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D049630:Esophageal Sphincter, Lower / Q000187:drug effects* / Q000502:physiology; D005764:Gastroesophageal Reflux / Q000188:drug therapy*; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D054328:Proton Pump Inhibitors / Q000494:pharmacology; D064750:Rabeprazole / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats
chemical_list: D054328:Proton Pump Inhibitors; D064750:Rabeprazole; D002217:Carbachol