A comparison of hyperbaric oxygen versus hypoxic cerebral preconditioning in neonatal rats.

Published

Journal Article

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.

Full Text

Duke Authors

Cited Authors

  • Freiberger, JJ; Suliman, HB; Sheng, H; McAdoo, J; Piantadosi, CA; Warner, DS

Published Date

  • February 23, 2006

Published In

Volume / Issue

  • 1075 / 1

Start / End Page

  • 213 - 222

PubMed ID

  • 16458861

Pubmed Central ID

  • 16458861

International Standard Serial Number (ISSN)

  • 0006-8993

Digital Object Identifier (DOI)

  • 10.1016/j.brainres.2005.12.088

Language

  • eng

Conference Location

  • Netherlands