The effect of oral alanine on blood glucose and glucagon in the human newborn infant.

Plasma glucose, glucagon, and insulin responses to oral feedings of L-alanine were assessed in 44 healthy term infants during the first three days of life. Alanine administration produced significant increases in glucagon and glucose concentrations on day 1, but not on days 2 and 3. These increases occurred within 30 minutes (mean and SEM for glucagon, 127 plus or minus 7 to 219 plus or minus 16 pg/ml, P smaller than 0.001; glucose, 45 plus or minus 3 to 60 plus or minus 7 mg/100 ml, P smaller than 0.01) and persisted at the P smaller than 0.05 level at four hours. Responsiveness to alanine seemed to be related to the baseline blood glucose levels since constant infusions of glucose inhibited the response; These results indicate that the pancreatic islet alpha cell secretion mechanism(s) is functioning in the newborn.