EFFECT OF AMINO-ACIDS ON LOWER ESOPHAGEAL SPHINCTER CHARACTERISTICS AND GASTROESOPHAGEAL REFLUX IN HUMANS

The effect of a commercially available mixed amino acids solution, whe n given either intravenously or intragastrically, on lower esophageal sphincter (LES) pressure, frequency of transient LES relaxations (TLES Rs) and gastroesophageal reflux (GER) was investigated in six healthy volunteers. LES pressure and esophageal pH were simultaneously recorde d on three separate occasions 1 hr before (basal) and 3 hr during intr avenous or intragastric infusion of amino acids (250 mg protein/kg/hr) or saline (control). No significant changes in LES pressure were seen in the control experiment. Intravenous amino acids caused a rapid and sustained (P < 0.01) decrease in LES pressure whereas intragastric am ino acids decreased LES pressure only gradually and temporarily (P < 0 .01). In the three experiments no significant differences were observe d in TLESR frequency, the number of GER episodes, the mechanism of ref lux, or duration of acid exposure. In healthy subjects both intragastr ic and, especially, intravenous infusion of amino acids significantly decrease LES pressure but do not affect the frequency of TLESRs or GER episodes during a continuous liquid gastric load.