Plasma amino acids neonatal

Nutrition may have a considerable effect. A high intake of milk protein in neonates will result in an increase in most plasma amino acids, especially methionine and tyrosine. Canned infant formulae may contain homocitrulline, which may appear in the patient s urine. White meat (chicken ) will contain carnosine, anserine, and... 

Plasma amino acid concentrations are high during the first days of life, especiaUy in premature neonates, but they tend to be low in infants with birth weights low for their gestational age because of placental insufficiency. Maternal values are low in the first half of pregnancy. In adults, increased plasma levels of homocysteine have been hnked to increased risk of heart disease (see Chapters 26 and 44). ... 

Age does not have a major influence on amino acid levels, with exception of the neonatal period. Premature babies may have underdeveloped hepatic and renal function, leading to increased tyrosine and methionine in their plasma as well as enhanced urinary losses of cystine, lysine, glycine, proline, hydroxyproline, and cystathionine. Taurine levels are generally increased in the first days of life. 

Argininosuccinic Aciduria Amino Acid Levels in Plasma, Cerebrospinal Fluid (CSF), and Urine in a Neonate with the Fulminating Condition... 

Particular interest attaches to these amino acids which are intermediary metabolites of the urea cycle, and which are normally present in the plasma, ornithine, citrulline, and arginine. Earlier reports do not mention the levels of these amino acids. Moser et al. (M13) found a normal plasma ornithine level in their two patients, but the citrulline was, as would be expected, several times the normal level, while the plasma arginine was at the lower limit of normal. In the cerebrospinal fluid also the citrulline level was greatly increased, while the ornithine and arginine levels were normal. Similar results were obtained also by Carton et al. (C3) in their neonate who died at 6 days old, and by Levin et al. (L5, Lll), also in a neonate who died in the first week of life. In the last two cases, however, the levels of citrulline were considerably higher than in the older patient of Moser et al. (M13) at 2.2 mg and 3.0 mg/100 ml, compared with a level of only 0.77 mg/100 ml for Moser s... 

---