A comparison of hyperbaric oxygen versus hypoxic cerebral preconditioning in neonatal rats
Autor: | Claude A. Piantadosi, Huaxin Sheng, Hagir B. Suliman, David S. Warner, Jessica D. McAdoo, John J. Freiberger |
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Rok vydání: | 2006 |
Předmět: |
medicine.medical_specialty
Central nervous system Ischemia Biology medicine.disease_cause Neuroprotection Aconitase Internal medicine medicine Animals Potency Hypoxia Brain Ischemic Preconditioning Molecular Biology Hyperbaric Oxygenation Cerebral infarction General Neuroscience Cerebral Infarction medicine.disease Rats Death medicine.anatomical_structure Endocrinology Animals Newborn Brain Injuries Anesthesia Ischemic preconditioning Neurology (clinical) Oxidative stress Developmental Biology |
Zdroj: | Brain Research. 1075:213-222 |
ISSN: | 0006-8993 |
Popis: | The potency of hyperbaric preconditioning (HBO-PC) is uncertain compared to well-validated ischemic or hypoxic models and no studies have directly compared HBO-PC to hypoxic preconditioning (HPC). We subjected rat pups to unilateral carotid cauterization followed by 90 min (min) of hypoxia using 8% O(2). Three HBO-PC regimes (maximum 2.5 atmospheres for 150 min) were compared to HPC (150 min of 8% O(2)) for changes in mortality and brain weight. Preconditioning-induced oxidative stress was assessed using aconitase activity and manganese superoxide dismutase (MnSOD) transcript levels. Initial brain weight data revealed a large coefficient of variation and compelled an examination of the temperature sensitivity of the model that revealed a narrow optimal range of 35 to 37 degrees C of variability in brain injury and mortality. With rigorous temperature control, high dose HBO-PC and HPC showed comparable anatomic (mean hemispheric weight decrease: control 42%, HPC 25% (P=0.01), HBO-PC 26% (P=0.01) and mortality protection (control 14.7%, HPC 5.9% HBO-PC 5.7%, P=0.001). High dose HBO-PC, but not HPC, suppressed aconitase activity by 65% at 24 h after the preconditioning stimulus (P=0.001). In contrast, MnSOD mRNA increased 2.5-fold at 24 h after HPC (P=0.007) but not after high dose HBO-PC. Thus, when temperature variability is eliminated, HBO-PC and HPC elicit similar preconditioning efficacy in neonatal brain but invoke different defenses against oxidative stress. |
Databáze: | OpenAIRE |
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