Postischemic administration of idazoxan, an alpha-2 adrenergic receptor antagonist, decreases neuronal damage in the rat brain

J Cereb Blood Flow Metab. 1989 Apr;9(2):171-4. doi: 10.1038/jcbfm.1989.25.


The effect of an alpha-2 receptor antagonist, idazoxan, on ischemic neuronal damage in the hippocampus and neocortex was studied in rats following 10 min of forebrain ischemia. Idazoxan was given 0.1 mg/kg i.v. immediately after recirculation, followed by 48 h of continuous infusion at a rate of 10 micrograms/kg/min. A histopathological examination of the CA1 region of the dorsal hippocampus and neocortex from each hemisphere was made on paraffin-embedded sections following 7 days of survival. In ischemic animals receiving an infusion of saline, 71% of the neurons in the hippocampal CA1 region were degenerated. In contrast, in the idazoxan-treated animals only 31% of the neurons were irreversibly damaged (p less than 0.01). We conclude that postischemic administration of the alpha-2 antagonist idazoxan protects neurons against damage following cerebral ischemia. Rapid postischemic administration of alpha-2 adrenergic receptor antagonists could be an effective treatment after stroke and cardiac arrest.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adrenergic alpha-Antagonists / therapeutic use*
  • Animals
  • Brain Diseases / drug therapy*
  • Brain Diseases / etiology
  • Brain Ischemia / complications
  • Brain Ischemia / drug therapy*
  • Dioxanes / therapeutic use*
  • Dioxins / therapeutic use*
  • Idazoxan
  • Male
  • Neurons / drug effects
  • Rats


  • Adrenergic alpha-Antagonists
  • Dioxanes
  • Dioxins
  • Idazoxan