The function of the gastroesophageal sphincter (GES) to eructate gas before and after
vagotomy was investigated in conscious, fed dogs. Gastric and GES pressures were measured in 5 dogs, using a perfused 4-lumen
catheter with a Dent sleeve. To induce
eructation,
nitrogen gas was insufflated (440 ml/min) into the stomach through 1 channel of the
catheter. After base-line studies were completed on each dog, bilateral
truncal vagotomy was performed 5 cm cranial to the diaphragm. Mean (+/- SE) GES pressure was 51.5 +/- 1 mm of Hg before
vagotomy and 28 +/- 1.7 mm of Hg after
vagotomy (P less than 0.001). Mean gastric contraction rates were the same, 4.91 +/- 0.11/min and 4.78 +/- 0.06/min in dogs before and after
vagotomy, respectively. During insufflation, gastric pressures increased to 11.8 +/- 0.7 mm of Hg before
eructation in dogs before
vagotomy and to 18.4 +/- 0.8 mm of Hg in dogs after
vagotomy (P less than 0.001).
Eructation occurred at intervals of 1.79 +/- 0.09 minutes before
vagotomy and 5.71 +/- 0.41 minutes after
vagotomy (P less than 0.001).
Atropine resulted in an interval of 1.98 +/- 0.18 minutes before
vagotomy.
Eructation was not seen in 2 dogs after
vagotomy and was sometimes not seen in the 3 others. Gastroesophageal sphincter pressure in dogs before
vagotomy began to decrease 4.5 +/- 0.2 s before the GES-pressure gradient disappeared, and GES pressure remained there for 5.3 +/- 0.3 s before the gradient began to return.(ABSTRACT TRUNCATED AT 250 WORDS)