[Organic acids including alpha-keto acids. Their importance and gaschromatographic-mass spectrometric analysis in serum and urine of infants].

: Alpha-ketoacids are of some importance as intermediary metabolic products of aminoacids. Analysis of alpha-ketoacids has been difficult due to their ketogroups. A newly applied method is described by which these ketogroups are transformed to oximes. Linearity, massspectrometric verification, stability, sensitivity, and extractability allow the application to physiologic fluids: 1. when challenged with oral 1-leucine, children with maple syrup urine disease show an increase in all three branched-chain alpha-ketoacids; 2. apparently branched-chain alpha-ketoacids play a major role in the pathogenesis of the so-called ketotic hypoglycemia; 3. infants, newborns, and prematures have higher serum concentrations and higher urinary excretion of organic acids including the alpha-ketoacids than oder children; 4. even when humanized milk is fed there appears to be a higher metabolic load in newborns and prematures than under human milk; 5. tyrosine and its organic acids pHPPA, pHPLA, and pHPAA are significantly increased in newborns and prematures when humanized milk versus real human milk is fed. These are further reasons, among many others, to prefer human milk in infant feeding over all artificial products.