Original article Effects of ursodeoxycholic acid in esophageal motility and the role of the mucosa. An experimental study M. S. Rocha, 1,2 F. A. Herbella, 1 J. C. Del Grande, 1 A. T. Ferreira, 3 C. Tahan, 3 M. G. Patti 4 1 Department of Surgery, Escola Paulista de Medicina, Federal University of Sao Paulo, Sao Paulo, 2 Department of Surgery, Unimontes, Montes Claros, Minas Gerais, 3 Department of Biophysics, Escola Paulista de Medicina, Federal University of Sao Paulo, Sao Paulo, Brazil; and 4 Department of Surgery, University of Chicago, Chicago, Illinois, USA SUMMARY. Esophageal motor abnormalities are frequently found in patients with gastroesophageal reflux disease. The role of bile in reflux-induced dysmotility is still elusive. Furthermore, it is questionable weather mucosal or muscular stimulation leads to motor dysfunction. The aims of this study were to analyze (i) the effect of bile in the amplitude of esophageal contractions; and (ii) the effect of mucosal versus muscular stimulation. Eighteen guinea pig esophagi were isolated, and its contractility assessed with force transducers. Three groups were studied. In group A (n = 6), the entire esophagus was incubated in 100 mmL ursodeoxycholic acid for 1 hour; in group B (n = 6) the mucosal layer was removed and the muscular layer incubated in 100 mmL ursodeoxycholic acid for 1 hour; and in group C (n = 6) (control group) the entire esophagus was incubated in saline solution. In all groups, five sequential contractions induced by 40 mm KCl spaced by 5 minutes were measured before and after incubation. Contractions amplitudes before incubation were 1.319 g, 0.306 g, and 1.795 g, for groups A, B, and C, respectively. There were no differences between groups A and C (P = 0.633), but there were differences between groups A and B (P = 0.039), and B and C (P = 0.048). After incubation amplitude of contraction were 0.709 g, 0.278 g, and 1.353 g for groups A, B, and C, respectively. Only group A showed difference when pre and post-stimulation amplitudes were compared (P = 0.030). Our results show that (i) bile exposure decreases esoph- ageal contraction amplitude; and (ii) the esophageal mucosa seems to play an important role in esophageal motility. KEY WORDS: bile reflux, esophageal motility, gastroesophageal reflux disease, ursodeoxycholic acid. INTRODUCTION Different clinical studies have shown the association of gastroesophageal disease (GERD) and esophageal dysmotility. 1,2 Although most series focused on the detection of acid reflux, studies with bilitec and mul- tichannel intraluminal impedance also demonstrated the presence of non-acid reflux in patients with GERD and esophageal motor disorders. 3 Interest- ingly, medical treatment for GERD focused on acid blockage shows little effect on esophageal motor disorders. 4,5 On the other side, surgical therapy (fundoplication) for GERD is nonselective in the pre- vention of acid or bile reflux and has shown to ame- liorate esophageal dysmotility. 6 This may suggest an important role of bile in reflux-induced dysmotility. It must be remembered; however, the fact that most episodes of reflux consist of mixed acid and non-acid substances make difficult the evaluation of the role Address correspondence to: Dr Fernando A. M. Herbella, MD, ISDE member, Hospital Sao Paulo, Surgical Gastroenterology, Division of Esophagus and Stomach, Rua Diogo de Faria 1087 cj 301., Sao Paulo, SP 04037-003, Brazil. Email: herbella.dcir@epm.br Author’s contribution: MSR: conception and design, acquisition of data, analysis and interpretation of data, drafting the article, final approval of the version to be published. FAH: conception and design, acquisition of data, analysis and interpretation of data, drafting the article, final approval of the version to be published. JCDG: review for intellectual content, final approval of the version to be published, ATF: review for intellectual content, final approval of the version to be published. CT: acquisition of data, analysis and interpretation of data, final approval of the version to be published. MGP: review for intellectual content, final approval of the version to be published. Grant support: Dr Marcelo S. Rocha was supported by a federal governmental grant from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). Diseases of the Esophagus (2011) 24, 291–294 DOI: 10.1111/j.1442-2050.2010.01137.x © 2010 Copyright the Authors Journal compilation © 2010, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus 291 Downloaded from https://academic.oup.com/dote/article/24/4/291/2328479 by guest on 05 January 2023