Gastrin, motilin and pancreatic polypeptide levels after two different parenteral regimens in infants.

We studied the effect of 2 different parenteral regimens upon gastrin, motilin and pancreatic polypeptide (PP) levels in infants. In 15 children, aged 1-25 months, plasma peptide levels were measured by radioimmunoassay in the fasting state and after a 2-h infusion of either a mixture of amino acids, glucose and lipids (A) or a mixture of amino acids and glucose (B) only. Wide interindividual fluctuations were noted, especially for motilin and PP, but, except for PP, intraindividual fluctuations were low. Indeed, a good correlation was found, not only between the 2 pre-infusion levels, but also between pre- and postinfusion levels in both experiments. In fact for all 3 peptides, pre- and postinfusion levels differed only slightly and non-significantly. We conclude that during parenteral feeding levels of motilin, PP and gastrin remain practically unchanged and are not influenced by the addition of lipids. In addition, during the observation period basal levels did not change, indicating that the mechanisms regulating basal secretion were not affected.