Cerebrospinal fluid levels of amino acids in infants and young children with chronic renal failure.

Chronic renal failure (CRF) is associated, especially in young children, with delayed cognitive development of unknown origin. As cerebrospinal fluid (CSF) reflects the composition of the extracellular fluid of the brain, not only plasma but also CSF amino acids concentrations were determined in 8 infants (age 2-8 months) and 3 children (age 26, 32 and 56 months) with CRF (creatinine clearance 13 ± 9 ml/min/ 1.73 m 2 ). In three of these children investigations were repeated after six weeks of CAPD treatment. In the infants, a significant decrease was found in CSF of (-aminobutyric acid, valine, isoleucine, leucine, tyrosine, tryptophane, histidine and n-(-methyl-1-lysine, whereas there was a significant increase of 3-methylhistidine. In plasma serine, valine, leucine, tyrosine and histidine were significantly decreased, whereas there was a significant increase of aspartic acid, citrulline, and 3-methylhistidine. These abnormalities remained constant after the start of CAPD except for the normalization in CSF and plasma of 3-methylhistidine. These data indicate a generalized disturbance of amino acids in young children with CRF. An abnormal substrate is offered to the neurons and astroglia in children with CRF.