Glycine and other neurotransmitter amino acids in cerebrospinal fluid in perinatal asphyxia and neonatal hypoxic-ischaemic encephalopathy.

Abstract

The aim of this study was to evaluate the concentrations of neurotransmitter amino acids in the cerebrospinal fluid (CSF) of asphyctic newborns, and to establish whether these concentrations are related to the degree of hypoxic-ischaemic encephalopathy (HIE). Levels of glutamate, aspartate, glycine and taurine in CSF were measured in 48 full-term newborns during the first 2 d of life. Thirty-nine of these newborns had birth asphyxia and were divided into three groups: 11 without HIE, 19 with mild HIE and 9 with moderate HIE. None suffered from severe HIE. They were compared with a control group of 9 non-hypoxic newborns. Determinations of the amino acids in CSF were made by chromatography and expressed as micromol/l (mean+/-SD). CSF glycine value was related to erythrocyte count, and CSF taurine value was related to its plasmatic level. Levels of CSF glycine were related to the severity of HIE (p=0.020): control (12.08+/-4.04 micromol/l), without HIE (12.49+/-4.04 micromol/l), mild HIE (12.14+/-3.83 micromol/l), and moderate HIE (19.1+/-10.08 micromol/l; p < 0.05 versus mild HIE), even after removing the influence of red cells in CSF.