Effect of distension of the pharynx and esophagus on the stomach in dogs: experimental evidence for a pharyngoesophagogastric reflex.

PURPOSE: To study the effect of pharyngeal and esophageal distension on the pressure within the stomach aiming at assessing the stomach condition during passage of food boli through the pharynx and esophagus.

METHODS

12 dogs (mean weight 16.2 +/- 3.3 kg) were studied. With the animal under anesthesia, a 4-Fr manometric catheter was introduced into the stomach and a 2-Fr balloon-tipped catheter into the pharynx. The gastric pressure response to pharyngeal and esophageal distension, each at a time, was recorded. Distension was performed in increments of 2 ml of water up to 6 ml. The test was repeated while the pharynx, esophagus or stomach were separately anesthetized using 2% xylocaine. Bilateral truncal vagotomy was done in 4 dogs and the gastric response to pharyngoesophageal distension studied.

RESULTS

Pharyngeal distension produced a significant pressure drop of the corpus of the stomach (p < 0.05); the pyloric antrum showed no response. Upper, middle or lower esophageal distension produced gastric response similar to that evoked by pharyngeal distension. The gastric response was abolished on distension of the anesthetized pharynx or esophagus, when the corpus was anesthetized, or after bilateral vagotomy.

CONCLUSION

The proximal gastric dilatation on pharyngeal and esophageal distension postulates a reflex relationship between the two actions which we call 'pharyngoesophagogastric reflex'. This reflex is suggested to dilate the proximal stomach preparatory to receiving food boli from the esophagus; it was abolished after anesthetizing its possible two arms arising from the pharyngoesophagus and the stomach, or after vagotomy.