Effect of transient hypoxia on oxygenation of the developing rat brain: relationships among haemoglobin saturation, autoregulation of blood flow and mitochondrial redox state.

Published

Journal Article

Multi-wavelength, differential spectroscopy was used to examine the effects of transient hypoxia on oxygen delivery and intracellular utilization in the brain of developing rats. The in vivo redox status of cytochrome a,a3 was compared simultaneously with changes in relative haemoglobin saturation and blood volume in the cerebral cortex during lowered FiO2. During hypoxia, neonates maintained their intracellular cytochrome a,a3 redox state as well as did adults, but did so through unusual characteristics, including: (1) maintenance of haemoglobin oxygenation at lower FiO2; (2) regulation of cerebral blood volume at blood pressures below the point at which autoregulation would fail in the adult; and (3) the capacity to tolerate a greater reduction of cytochrome a,a3 relative to haemoglobin desaturation at lowered FiO2. These data suggest that mechanisms which protect the neonate from hypoxic insult involve preservation of oxygen delivery, increased respiratory compensation for metabolic acidosis, and maintenance of cellular energy requirements predominantly through anaerobic metabolism.

Full Text

Duke Authors

Cited Authors

  • Sylvia, AL; Seidler, FJ; Slotkin, TA

Published Date

  • November 1989

Published In

Volume / Issue

  • 12 / 5

Start / End Page

  • 287 - 292

PubMed ID

  • 2634069

Pubmed Central ID

  • 2634069

International Standard Serial Number (ISSN)

  • 0141-9846

Language

  • eng