[Plasma concentrations of amino acids, urea nitrogen and ammonia in 1 to 2 month-old low birth weight premature infant (author's transl)].

: The aim of the present study was to measure the plasma concentrations of amino acids under different diets in preterm neonates whose birthweights were less than 1,350 g and gestational ages less than 34 weeks, and to compare these results with the plasma concentrations of amino acids in full term infants who were exclusively breast fed. At the end of the second month, these concentrations in preterm breast fed infants were similar to those in full term infants except for significantly lower levels of lysine. The addition of 46% humanized formula to breast milk did not change the concentrations of amino acids. The blood levels of urea nitrogen and ammonia were not different in preterm and full term infants; they were not altered by the addition of the formula.