Motility changes in opossum esophagus from experimental esophagitis

Abstract

We assessed how acute inflammation affects the contractile activity of the esophageal body. Two models of esophagitis were used: nine opossums had an esophageal perfusion of 100 meq hydrochloric acid for 2 hr and were studied at 24 hr. Ten had the perfusion for 4 h and their esophagitis were studied in vitro after 72 hr. Comparisons were made in all instances to animals who had esophageal saline perfusion for identical periods. All acid-perfused animals developed gross and histologic evidence of mucosal inflammation; in three animals, inflammatory changes extended into the submucosa and the muscularis propria. Manometric recordings in the acid-perfused animals revealed esophageal shortening, frequent failure of primary peristalsis and frequent occurrence of spontaneous contractions. Recordings of isometric tension of muscle in vitro revealed spontaneous contractions in strips from the mucosa and from the circular and from the longitudinal muscle. The amplitude of contractions in response to electrical stimulation was decreased, but the duration of contractions was increased largely because of a prolonged recovery phase. These changes in mechanical response occurred with stimulus parameters directed at both the muscle and the intrinsic nerves. We conclude that esophageal inflammation can lead to an increased irritability and decreased stimulus response of the smooth muscle of the esophagus even where it is not directly involved in an inflammatory response. These changes correspond to the functional abnormalities of the esophagus seen in patients with reflux esophagitis.

Effect of repeated cycles of acute esophagitis and healing on esophageal peristalsis, tone, and length

“…In agreement with previous studies, we found that acute esophagitis significantly reduced the frequency and amplitude of peristaltic contractions in the esophagus (7,16,24). Previous animal studies used acute experiments and did not follow up on the spontaneous evolution of motility changes.…”

“…Previous animal studies with acute experimental esophagitis demonstrated an increased intraesophageal baseline pressure (16) or a high baseline tension in muscle strips from the esophageal body (24). To the best of our knowledge, this is the first description of esophageal tone changes, measured with a barostat, during acute esophagitis.…”

“…In cats and opossums, acid perfusion-induced acute esophagitis provokes failure of primary peristalsis, frequent spontaneous contractions (16,24), esophageal shortening (21), and reduced LES pressure (7,23).…”

Effects of Aging and Acid Reflux on Esophageal Motility

“…In the previous study, LES pressure, the success rate, and the amplitude of primary peristalsis in patients with RE increased after treatment, compared with before treatment [15]. In some animal experiments, it has been reported that LES pressure or the amplitude of peristalsis decreased after experimental esophagitis [16,17,18]. These results are consistent with our results; however, there is a contrary view.…”

Gender Differences in Pain and Biomechanical Responses After Acid Sensitization of the Human Esophagus

“…However, we did not find any gender-related differences. Such hyperreactivity was also seen in animal studies (40). Acid perfusion may result in sensitization of mucosal afferents as well as central hyperexcitability (23,41).…”