Plasma concentrations of gastrin and somatostatin after breast feeding in 4 day old infants.

The plasma concentrations of gastrin and somatostatin were measured by radioimmunoassay before and after breast feeding in healthy 4 day old infants who had been born at full term. The mean (SD) concentrations of gastrin and somatostatin before breast feeding were 120 (30) pmol/l and 35 (12) pmol/l, respectively. Breast feeding in these infants was not followed by increased concentrations of gastrin and somatostatin in peripheral blood. High preprandial peptide concentrations, as seen during the neonatal period may limit the further release of peptide after feeding.