Dexamethasone increases plasma amino acid concentrations in bronchopulmonary dysplasia

Nine ventilated low birthweight babies were treated with dexamethasone (0.6 mg/kg/day). Appreciable suppression of weight gain was accompanied by uraemia and significant increases in the concentration of all amino acids except phenylalanine, tyrosine, threonine, and glutamate. Ornithine, citrulline, alanine, glutamine, and cystine concentrations increased threefold or more. The findings could not be explained by changes in dietary intake and presumably reflect pronounced catabolism, though the effects of dexamethasone on intermediary metabolism and membrane transport could also play a part.