Vol. 2, Issue 2, Article 1 Neurographics logo Radaideh, et al.

[an error occurred while processing this directive]

 

Metabolic neuronal derangements secondary to hypoxia
  • The brain is a highly aerobic tissue, with oxygen rather than any other metabolic substrate serving as the limiting substance for energy production.
  • As the oxygen tension within the cell decreases, there is loss of oxidative phosphorylation and decreased generation of ATP in the mitochondria.
  • Intracellular ATP production becomes dependent on anaerobic glycolysis in the cytoplasm. This produces small quantities of ATP not sufficient to maintain cellular metabolism.

Each glucose molecule produces:

  • In aerobic metabolism 36-38 ATP with oxidative phosphorylation in the mitochondria
  • In anaerobic metabolism in hypoxic conditions 2 ATP and 2 molecules of lactic acid in the cytoplasm

  • The activity of the plasma membrane energy-dependent sodium pump (Na+ , K+ -ATPase) is reduced.
  • Failure of this active transport system causes sodium to accumulate intracellularly with diffusion of potassium out of the cell.
  • The net gain of solute is accompanied by isosmotic gain of water resulting in cellular swelling.

[2a]
[2b]

 



Copyright © 2003. All rights reserved.
Use of this material without written consent of the author is prohibited.

Return to Neurographics Main Page