title: Effect of intravenous L-alanine administration on plasma glucose, insulin and glucagon, blood pyruvate, lactate and beta-hydroxybutyrate concentrations in newborn infants. Study in term and preterm newborn infants.
abstract: Ten term and eleven preterm newborn infants with appropriate weights for their gestational age were infused for one minute with L-alanine (150 mg/kg) at the age of 29 to 76 hours (mean 48 hours) and circulating levels of glucose, lactate, pyruvate, D-betahydroxybutyrate (D-BOHB), insulin and glucagon were monitored. Plasma glucose concentrations increased from 2.7 +/- 0.16 (mean +/- S.E.M.) to 3.7 +/- 0.2 mmol/l after 50 min (p less than 0.01) in term infants. In preterm infants, after an initial decrease of the glucose level from 3.1 +/- 0.16 to 2.6 +/- 0.16 mmol/l (p less than 0.05), it returned to the baseline level at 50 min: 3.0 +/- 0.2 mmol/l. The blood concentration of D-BOHB decreased in term infants from 192 +/- 37 to 112 + 6 micrometer/l (p less than 0.01) after 40 min. In preterms, its decrease was not significant (p greater than 0.05). Plasma glucagon level rose from 53 +/- 5 to 70 +/- 8 pmol/l after ten minutes (p less than 0.01) in terms infants and from 61 +/- 6 to 75 +/- 9 after 20 min (p less than 0.01) in preterm infants. There were no significant changes in plasma insulin concentrations in either group. Forty minutes after L-alanine infusion, I/G ratios were lower in preterm infants (1.26 +/- 0.14) than in term infants (1.71 +/- 0.25) (p less than 0.01). There was no relationship between the glycemic responses to L-alanine and the basal levels of D-BOHB. The data suggest that the glycemic effect of L-alanine infusion and circulating glucagon depends upon a specific stage in maturation. The antiketogenic effect of L-alanine infusion is observed in term infants as in adults.
mesh_terms: D000409:Alanine / Q000008:administration & dosage / Q000494:pharmacology*; D001786:Blood Glucose / Q000032:analysis; D005934:Glucagon / Q000097:blood*; D006801:Humans; D006885:Hydroxybutyrates / Q000097:blood*; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D007328:Insulin / Q000097:blood*; D007773:Lactates / Q000097:blood*; D011773:Pyruvates / Q000097:blood*
chemical_list: D001786:Blood Glucose; D006885:Hydroxybutyrates; D007328:Insulin; D007773:Lactates; D011773:Pyruvates; D005934:Glucagon; D000409:Alanine