Effects of oral alanine feeding on blood glucose, plasma glucagon and insulin concentrations in small-for-gestational-age infants.

The effects of oral alanine feeding on glucose homeostasis were evaluated in 21 infants who were small for gestational age and 26 who were appropriate for gestational age. In the first 24 hours, basal plasma alanine concentrations were higher in the former. Oral alanine feedings produced a significant rise over baseline levels of plasma alanine and glucagon concentrations in both groups. The blood glucose and plasma insulin concentrations also increased significantly in infants who were appropriate but not in those who were small for gestational age. At 25 to 96 hours of age, plasma glucagon, insulin and blood glucose concentrations did not change after the alanine feeding in either group. These data indicate that in the normally nourished infant (appropriate forgestational age), gluconeogenic amino acid (alanine) enhances hepatic glucose output. This phenomenon is not observed in the mainourished infants (small for gestational age), a point that may reflect decreased glycogen stores and ineffective gluconeogenic enzyme system in such infants.