Temporal patterns of interstitial pyruvate and amino acids after subarachnoid haemorrhage are related to the level of consciousness--a clinical microdialysis study

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Temporal patterns of interstitial pyruvate and amino acids after subarachnoid haemorrhage are related to the level of consciousness--a clinical microdialysis study. / Zetterling, Maria; Hillered, Lars; Samuelsson, Carolina; Karlsson, Torbjörn; Enblad, Per; Ronne-Engström, Elisabeth.

In: Acta Neurochirurgica, Vol. 151, No. 7, 07.2009, p. 771-80.

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Zetterling, Maria ; Hillered, Lars ; Samuelsson, Carolina ; Karlsson, Torbjörn ; Enblad, Per ; Ronne-Engström, Elisabeth. / Temporal patterns of interstitial pyruvate and amino acids after subarachnoid haemorrhage are related to the level of consciousness--a clinical microdialysis study. In: Acta Neurochirurgica. 2009 ; Vol. 151, No. 7. pp. 771-80.

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TY - JOUR

T1 - Temporal patterns of interstitial pyruvate and amino acids after subarachnoid haemorrhage are related to the level of consciousness--a clinical microdialysis study

AU - Zetterling, Maria

AU - Hillered, Lars

AU - Samuelsson, Carolina

AU - Karlsson, Torbjörn

AU - Enblad, Per

AU - Ronne-Engström, Elisabeth

PY - 2009/7

Y1 - 2009/7

N2 - BACKGROUND: Temporal patterns of brain interstitial amino acids after subarachnoid haemorrhage (SAH) were studied in relation to energy metabolite levels and to the severity of the initial global ischaemia as reflected by the level of consciousness at admission.METHOD: Intracerebral microdialysis was used to measure brain interstitial amino acids and the energy metabolites glucose, lactate, and pyruvate during five days in 19 patients. Patients who were conscious (n = 11) were compared to those who were unconscious on admission (n = 8).FINDINGS: Eight non-transmitter amino acids (alanine, asparagine, glutamine, isoleucine, leucine, phenylalanine, serine and tyrosine), as well as glycine and pyruvate showed a pattern of increasing concentrations starting at 60-70 h after the onset of SAH. The conscious patients showed more pronounced elevations of non-transmitter amino acids, glycine, taurine and pyruvate compared to the unconscious patient group. Pyruvate levels were initially critically low for all patients, then normalised in the conscious patients but remained low in the unconscious group.CONCLUSIONS: There was an increase of the cerebral interstitial levels of non-transmitter amino acids and glycine which correlated temporally to pyruvate levels, more pronounced in patients conscious on admission. Pyruvate levels in these patients normalised, but remained reduced in the unconscious patients. The increase of the non-transmitter amino acids and glycine could reflect an increased amino acid turnover in an attempt at repairing the injured brain, which could have been hampered by the lower pyruvate levels. Interstitial pyruvate may be a useful marker of the energy metabolic situation in the acutely injured brain.

AB - BACKGROUND: Temporal patterns of brain interstitial amino acids after subarachnoid haemorrhage (SAH) were studied in relation to energy metabolite levels and to the severity of the initial global ischaemia as reflected by the level of consciousness at admission.METHOD: Intracerebral microdialysis was used to measure brain interstitial amino acids and the energy metabolites glucose, lactate, and pyruvate during five days in 19 patients. Patients who were conscious (n = 11) were compared to those who were unconscious on admission (n = 8).FINDINGS: Eight non-transmitter amino acids (alanine, asparagine, glutamine, isoleucine, leucine, phenylalanine, serine and tyrosine), as well as glycine and pyruvate showed a pattern of increasing concentrations starting at 60-70 h after the onset of SAH. The conscious patients showed more pronounced elevations of non-transmitter amino acids, glycine, taurine and pyruvate compared to the unconscious patient group. Pyruvate levels were initially critically low for all patients, then normalised in the conscious patients but remained low in the unconscious group.CONCLUSIONS: There was an increase of the cerebral interstitial levels of non-transmitter amino acids and glycine which correlated temporally to pyruvate levels, more pronounced in patients conscious on admission. Pyruvate levels in these patients normalised, but remained reduced in the unconscious patients. The increase of the non-transmitter amino acids and glycine could reflect an increased amino acid turnover in an attempt at repairing the injured brain, which could have been hampered by the lower pyruvate levels. Interstitial pyruvate may be a useful marker of the energy metabolic situation in the acutely injured brain.

KW - Aged

KW - Amino Acids/analysis

KW - Biomarkers/analysis

KW - Brain/blood supply

KW - Brain Chemistry/physiology

KW - Brain Ischemia/etiology

KW - Consciousness Disorders/etiology

KW - Down-Regulation/physiology

KW - Energy Metabolism/physiology

KW - Extracellular Fluid/chemistry

KW - Female

KW - Glucose/analysis

KW - Humans

KW - Male

KW - Microdialysis/methods

KW - Middle Aged

KW - Pyruvic Acid/analysis

KW - Subarachnoid Hemorrhage/complications

KW - Time Factors

KW - Up-Regulation/physiology

KW - Vasospasm, Intracranial/etiology

U2 - 10.1007/s00701-009-0384-4

DO - 10.1007/s00701-009-0384-4

M3 - Article

VL - 151

SP - 771

EP - 780

JO - Acta Neurochirurgica

JF - Acta Neurochirurgica

SN - 0001-6268

IS - 7

ER -