INTRAVENOUS AMINO ACIDS STIMULATE GASTRIC ACID SECRETION IN INFANTS

Abstract

To determine the effect of an intravenous amino acid infusion on gastric acid secretion we measured acid secretion in 7 enterally fed chronically ill infants (age 3-7 mo, weight 2-6 kg) requiring intravenous supplements. Amino acids were emitted from intravenous solutions for 8 hr, and enteral feedings were omitted for 6 hr prior to studies on 2 consecutive days. On day 1 basal acid output (BAO) was 28±5 μmoles/kg.hr, and post-pentagastrin (6 μg/kg, s.c.) maximal acid output (MAO) was 99±20 μmoles/kg.hr. On day 2 BAO was determined and then acid output was measured for 4 hr following addition of amino acids (Aminosyn, Abbott) to the intravenous solution. The rate of amino acid infusion was 0.15 gm/kg.hr. Serum gastrin was measured by radioimmunoassay before and after amino acid infusion. All results were expressed as mean ± SEM.

Amino acid-stimulated acid output was significantly higher than BAD in the final 2 hr. The infusion of intravenous amino acids resulted in 1) an immediate and sustained increase in acid secretion 2) a 2-fold increase in acid secretion to 50% MAO, and 3) no significant change in serum gastrin concentration. We conclude that amino acids infused at a rate typical for parenteral nutrition stimulate gastric acid secretion in infants.