Effects of Cholecystokinin on Esophageal Motor Response to Distension in Asymptomatic Volunteers.

Abstract

Cholecystokinin (CCK) administration has been shown to reduce lower esophageal sphincter (LES) pressure in normal subjects in manometric studies. Functional luminal imaging probe (FLIP) panometry offers a method to assess esophageal motility in response to sustained distension though mechanisms related to this response remain unexplored. The aim of this study is to evaluate the effect of CCK-8 on the esophageal response to distension in asymptomatic volunteers using FLIP. Esophageal response to distension was studied in 7 asymptomatic volunteers (mean age ± SD [27 ± 2]; 86% female) before and after CCK-8 administration in a crossover study design. During sedated endoscopy, FLIP was performed twice with CCK-8 administered via intravenous push in one of 2 protocols: during filling (n = 4) or during emptying (n = 3). Esophagogastric junction distensibility index (EGJ-DI) at 60 mL fill volume and esophageal body contractile response patterns were analyzed. During the baseline FLIP study, all subjects had a contractile response with repetitive antegrade contractions both before and after CCK-8 administration. However, a sustained LES contraction or a sustained occluding contraction with esophageal shortening was observed in all subjects in the filling protocol, but in none during the emptying protocol. EGJ-DI was similar before and after CCK-8 during both filling (4.7 ± 1.9 mm2/mmHg vs 4.3 ± 1.8 mm2/mmHg) and emptying protocol (7.5 ± 1.4 mm2/mmHg vs 6.9 ± 0.6 mm2/mmHg). While EGJ-DI appeared unaffected by CCK-8 administration in asymptomatic volunteers, CCK induced spastic-reactive contractions of the LES during distention suggesting that exogenous CCK interferes with normal LES relaxation during secondary peristalsis.