Inhibition of the lower oesophageal sphincter by fat--a mechanism for fatty food intolerance.

The effect of fat and protein meals on the lower oesophageal sphincter pressure was tested in normal subjects using an infused open-tipped manometric system. After ingestion of a minced beef meal, the mean peak pressure at the lower oesophageal sphincter increased 5.8 +/- 1.5 mm Hg (+/- 1 SE). By contrast, ingestion of a corn oil meal resulted in a mean peak decrease of 7.8 +/- 1.9 mm Hg. Following the combined minced beef/corn oil meal, mean peak pressure decreased 3.0 +/- 2.1 mm Hg. Pentagastrin (3 mug/kg, subcutaneously) resulted in a mean peak increase of 20.6 +/- 7.0 mm Hg when given to the subjects in the fasting state, and produced an increase of only 8.4 +/- 1.7 mm Hg when given following the fat meal. Finally, after a mean peak decrease in pressure at the lower oesophageal sphincter of 6.8 +/- 1.0 mm Hg 15 minutes after the corn oil meal, gastric alkalinization with 30 ml of antacid resulted in a subsequent increase in sphincter pressure of 5.2 +/- 1.6 mm Hg. These data indicate: (1) Fat attenuates the effect of endogenous gastrin as well as exogenous pentagastrin stimulation of the lower oesophageal sphincter. (2) Fat-induced incompetency of the lower oesophageal sphincter can be effectively combated by gastric alkalinization in the form of antacids.