Background: The aim of this study was to investigate the inhibitory innervation of the lower esophageal sphincter in the presence of esophagitis.
Methods: Esophagitis was produced in five anesthetized cats with intraesophageal perfusion of HCl. Sphincter pressure responses were assessed with a sleeve catheter after administration of bethanechol, cholecystokinin octapeptide, and McNeil-A343 and with intraesophageal balloon distension.
Results: In the presence of esophagitis (1) resting lower esophageal sphincter pressure decreased; (2) the excitatory response to bethanechol was maintained; (3) there was a reduction in the excitatory response to McNeil-A343 and cholecystokinin at the highest dosages; (4) there was an increase in the potency of cholecystokinin and McNeil-A343 to produce an inhibitory response; (5) the inhibitory response to intraesophageal balloon distension was maintained; and (6) increased inhibitory responses took longer to normalize than the reduced excitatory responses.
Conclusions: Esophagitis decreases cholinergic excitation, but neural inhibition to the LES remains intact. These findings suggest that blocking intact inhibition may be a new therapeutic approach for esophagitis caused by gastroesophageal reflux.