TY - JOUR
T1 - Persistent neurochemical changes in neonatal piglets after hypoxia-ischemia and resuscitation with 100%, 21% or 18% oxygen
AU - Jantzie, Lauren L.
AU - Cheung, Po Yin
AU - Obaid, Laila
AU - Emara, Marwan
AU - Johnson, Scott T.
AU - Bigam, David L.
AU - Todd, Kathryn G.
N1 - Funding Information:
KG Todd is supported by the Heart and Stroke Foundation of Canada, the Canadian Institutes for Health Research (CIHR), The Canada Stroke Network, the Davey Research Fund and the Stollery Children's Hospital Foundation. P-Y Cheung is supported by CIHR and the Alberta Heritage Foundation for Medical Research (AHFMR). LL Jantzie is a recipient of a Canada Graduate Scholarship from the Natural Science and Engineering Research Council of Canada (NSERC) and a Doctoral Research Award from AHFMR. We are very grateful to Gail Rauw and Grace Chan BSCN, RN for their excellent assistance and technical expertise.
PY - 2008/4
Y1 - 2008/4
N2 - Background: Neonatal hypoxia-ischemia (HI) is a common complication of pregnancy and delivery. Conventional clinical practice is to resuscitate neonates with 100% O2, and evidence is building to suggest resuscitation with lower O2 concentrations is safer. Significant neurochemical changes are associated with HI injury and persistent changes in amino acids are related to cell death, therefore we used a swine survival model of neonatal HI-reoxygenation (HI/R) to investigate the effects of resuscitation with 100%, 21% or 18% O2 on amino acid neurotransmitters. Methods: In a blinded randomized fashion, following permanent ligation of the left common carotid artery, newborn pigs (1-4 d, 1.7-2.5 kg) received alveolar normocapnic hypoxia (FiO2 = 0.15, 2 h) and were reoxygenated with 18%, 21% or 100% O2. After a 4-day survival period, brain regions were processed for amino acid levels using high-performance liquid chromatography (HPLC). Results: Results showed that resuscitation with different O2 concentrations caused hemispheric and regional changes in all amino acids investigated including glutamate, alanine, γ-amino butyric acid, glycine and aspartate, 4 days post-HI. Resuscitation with 100% O2 significantly increased glutamate and glycine in the dorsal cortex contralateral to the ligated common carotid artery, compared to piglets resuscitated with 21% O2. Additionally, piglets resuscitated with 21% O2 had significantly lower alanine levels than those resuscitated with 18% O2. Conclusion: Significant resuscitation-dependent changes in amino acid neurotransmitters are still evident 4 days post-HI in the newborn piglet. These data suggest that persistent changes in neurochemistry occur 4 days after HI/R and further studies are warranted to elucidate the consequences of this on neonatal brain development.
AB - Background: Neonatal hypoxia-ischemia (HI) is a common complication of pregnancy and delivery. Conventional clinical practice is to resuscitate neonates with 100% O2, and evidence is building to suggest resuscitation with lower O2 concentrations is safer. Significant neurochemical changes are associated with HI injury and persistent changes in amino acids are related to cell death, therefore we used a swine survival model of neonatal HI-reoxygenation (HI/R) to investigate the effects of resuscitation with 100%, 21% or 18% O2 on amino acid neurotransmitters. Methods: In a blinded randomized fashion, following permanent ligation of the left common carotid artery, newborn pigs (1-4 d, 1.7-2.5 kg) received alveolar normocapnic hypoxia (FiO2 = 0.15, 2 h) and were reoxygenated with 18%, 21% or 100% O2. After a 4-day survival period, brain regions were processed for amino acid levels using high-performance liquid chromatography (HPLC). Results: Results showed that resuscitation with different O2 concentrations caused hemispheric and regional changes in all amino acids investigated including glutamate, alanine, γ-amino butyric acid, glycine and aspartate, 4 days post-HI. Resuscitation with 100% O2 significantly increased glutamate and glycine in the dorsal cortex contralateral to the ligated common carotid artery, compared to piglets resuscitated with 21% O2. Additionally, piglets resuscitated with 21% O2 had significantly lower alanine levels than those resuscitated with 18% O2. Conclusion: Significant resuscitation-dependent changes in amino acid neurotransmitters are still evident 4 days post-HI in the newborn piglet. These data suggest that persistent changes in neurochemistry occur 4 days after HI/R and further studies are warranted to elucidate the consequences of this on neonatal brain development.
KW - Amino acid neurotransmitters
KW - High-performance liquid chromatography
KW - Neonatal hypoxia-ischemia
KW - Neonatal resuscitation
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U2 - 10.1016/j.resuscitation.2007.10.008
DO - 10.1016/j.resuscitation.2007.10.008
M3 - Article
C2 - 18083289
AN - SCOPUS:39849107755
SN - 0300-9572
VL - 77
SP - 111
EP - 120
JO - Resuscitation
JF - Resuscitation
IS - 1
ER -