Concentrations of Organic Acids in the Urine of Healthy Newborn Children

Abstract

Urine concentrations of organic acids were determined by a gas chromatographic technique in healthy, full-term neonates at the ages of 2 and 5 days. Significant reductions in the interindividual variation were obtained by relating the levels of organic acids to urine creatinine concentration or osmolality. Citrate was the predominant organic anion found. Urine concentrations of fumarate, 3-hydroxy-3-methylglutarate, adipate, and suberate decreased during the first week of life, and their concentrations were significantly intercorrelated. It is suggested that these findings reflect the predominantly fat-utilising, hyperketonaemic state during the first days of life. The urine concentrations of the aromatic end-products, p-hydroxyphenylacetate and hippurate, increased during the first week of life, probably as an effect of dietary factors.

It is concluded that analysis of intermediary organic acids in urine could be of value in the assessment of the metabolic state in neonates.

References

Aksu

Morrow

III Barness

L. A.

(1974). Urinary excretion of non-nitrogenous organic acids by healthy infants and children. Clinical Chemistry, 20, 603–605.

Björkman

McLean

Steen

(1976). Organic acids in urine from human newborns. Clinical Chemistry, 22, 49–52.

Dalgliesh

C. E.

Horning

E. C.

Horning

M. G.

Knox

K. L.

Yarger

(1966). A gas-liquid-chromatographic procedure for separating a wide range of metabolites occurring in urine or tissue extracts. Biochemical Journal, 101, 792–810.

Finnström

(1971). Studies on maturity in newborn infants. III. Neurological examination. Neuropädiatric, 3, 72–96.

Finnström

(1972a). Studies on maturity in newborn infants. II. External characteristics. Acta Paediatrica Scandinavica, 61, 24–32.

Finnström

(1972b). Studies on maturity in newborn infants. VI. Comparison between different methods for maturity estimation. Acta Paediatrica Scandinavica, 61, 33–41.

Gregersen

Ingerslev

Rasmussen

(1977). Low molecular weight organic acids in the urine of the newborn. Acta Paediatrica Scandinavica, 66, 85–89.

Hagenfeldt

(1968). Gas chromatographic determination of organic acids in blood. Arkiv för Kemi, 29, 63–73.

Jellum

Stokke

Eldjarn

(1971). Screening for metabolic disorders using gas-liquid chromatography, mass spectrometry and computer technique. Scandinavian Journal of Clinical and Laboratory Investigation, 27, 273–285.

10.

Mamer

O. A.

Crawhall

J. C.

Tjoa

S. S.

(1971). The identification of urinary acids by coupled gas chromatography—mass spectrometry. Clinica Chimica Acta, 32, 171–184.

11.

McKeown

G. G.

Read

S. I.

(1965). Esterification and gas chromatography of some acids of the tricarboxylic acid cycle. Analytical Chemistry, 37, 1780–1781.

12.

Pettersen

J. E.

Jellum

Eldjarn

(1972). The occurrence of adipic and suberic acid in urine from ketonic patients. Clinica Chimica Acta, 38, 17–24.

13.

Thompson

J. A.

Markey

S. P.

(1975). Quantitative metabolic profiling of urinary organic acids by gas chromatography—mass spectrometry: Comparison of isolation methods. Analytic Chemistry, 47, 1313–1321.