Lower esophageal sphincter pressure and serum motilin levels.

The gastrointestinal hormone motilin has recently been proposed as having a physiological role in the determination of lower esophageal sphincter (LES) strength. The present study was performed to evaluate the effect of gastric alkalinization of LES pressure and serum motilin levels. Instillation of 0.1N NaHCO3 into the stomach resulted in a significant increase in LES pressure (P less than 0.01) without affecting serum motilin levels. No correlation was found between fasting serum motilin levels and resting LES pressure (r = -0.31). These observations do not support the theory that LES pressure increases during gastric alkalinization are mediated through motilin release.