title: The participation of the nitrergic pathway in increased rate of transitory relaxation of lower esophageal sphincter induced by rectal distension in dogs.
abstract: BACKGROUND
  The rectal distension in dogs increases the rate of transitory lower esophageal sphincter relaxation considered the main factor causing gastroesophageal reflux.
  
  
  OBJECTIVE
  The aim of this study was evaluate the participation of the nitrergic pathway in the increased transitory lower esophageal sphincter relaxation rate induced by rectal distension in anesthetized dogs.
  
  
  METHODS
  Male mongrel dogs (n = 21), weighing 10-15 kg, were fasted for 12 hours, with water ad libitum. Thereafter, they were anesthetized (ketamine 10 mg.Kg-1 + xylazine 20 mg.Kg-1), so as to carry out the esophageal motility evaluation protocol during 120 min. After a 30-minute basal period, the animals were randomly intravenous treated whith: saline solution 0.15M (1ml.Kg-1), L-NAME (3 mg.Kg-1), L-NAME (3 mg.Kg-1) + L-Arginine (200 mg.Kg-1), glibenclamide (1 mg.Kg-1) or methylene blue (3 mg.Kg-1). Forty-five min after these pre-treatments, the rectum was distended (rectal distension, 5 mL.Kg-1) or not (control) with a latex balloon, with changes in the esophageal motility recorded over 45 min. Data were analyzed using ANOVA followed by Student Newman-Keuls test.
  
  
  RESULTS
  In comparison to the respective control group, rectal distension induces an increase in transitory lower esophageal sphincter relaxation. Pre-treatment with L-NAME or methylene blue prevents (P<0.05) this phenomenon, which is reversible by L-Arginine plus L-NAME. However, pretreating with glibenclamide failed to abolish this process.
  
  
  CONCLUSIONS
  Therefore, these experiments suggested, that rectal distension increases transitory lower esophageal sphincter relaxation in dogs via through nitrergic pathways.
authors.affiliation: Departamento de Cirurgia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil.
authors.forename: Michel Santos
authors.initials: MS
authors.lastname: Palheta
authors.affiliation: Departmento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil.
authors.forename: José Ronaldo Vasconcelos da
authors.initials: JR
authors.lastname: Graça
authors.affiliation: Departmento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil.
authors.forename: Armênio Aguiar dos
authors.initials: AA
authors.lastname: Santos
authors.affiliation: Departmento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil.
authors.forename: Liziane Hermógenes
authors.initials: LH
authors.lastname: Lopes
authors.affiliation: Faculdade de Medicina Veterinária, Universidade Federal do Vale do São Francisco, Petrolina, PE, Brasil.
authors.forename: Raimundo Campos
authors.initials: RC
authors.lastname: Palheta Júnior
authors.affiliation: Departamento de Cirurgia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE, Brasil.
authors.forename: Miguel Ângelo
authors.initials: MÂ
authors.lastname: Nobre E Souza
mesh_terms: D000818:Animals; D004285:Dogs; D049630:Esophageal Sphincter, Lower / Q000502:physiology*; D004943:Esophagogastric Junction / Q000502:physiology*; D005769:Gastrointestinal Motility / Q000502:physiology; D008297:Male; D008365:Manometry; D026602:Nitrergic Neurons / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D019335:Nitroarginine / Q000494:pharmacology*; D010528:Peristalsis / Q000502:physiology*; D012007:Rectum / Q000502:physiology*; D012018:Reflex / Q000502:physiology
chemical_list: D019335:Nitroarginine