Immunohistochemical detection of inducible nitric oxide synthase, nitrotyrosine and manganese superoxide dismutase following hyperglycemic focal cerebral ischemia

Brain Res. 2001 Nov 9;918(1-2):10-9. doi: 10.1016/s0006-8993(01)02903-1.


We have characterized the temporal changes in iNOS, MnSOD and nitrotyrosine immune reactivity in a rat model of permanent middle cerebral artery occlusion under acute hyperglycemic or normoglycemic conditions followed by either 3- or 24-h recovery. We found that the macroscopic labeling pattern for all three antibodies colocalized with the ischemic core and penumbra which was determined by cresyl violet histological evaluation in adjacent sections. Hyperglycemia induced prior to ischemia resulted in earlier infarction which correlated with increased immunoreactivity for iNOS, MnSOD and nitrotyrosine. In the penumbral region of the frontal cortex, labeling of specific cell structures was largely limited to cortical neurons near the corpus callosum and was apparent earlier in the hyperglycemic rats. Increased polymorphonuclear leukocyte adhesion in blood vessels was observed at 24 h in the hyperglycemic group. At both of the recovery times studied, we observed only minor vascular staining for nitrotyrosine and none for iNOS. Our results are consistent with hyperglycemia resulting in an early and concomitant increase in both superoxide and nitric oxide production which can lead to peroxynitrite formation that then nitrates tyrosine residues. It would appear that hyperglycemic ischemia contributes to the early induction of key enzymes involved in nitric oxide bioavailability.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Vessels / enzymology
  • Blood Vessels / pathology
  • Blood Vessels / physiopathology
  • Brain Ischemia / complications*
  • Brain Ischemia / enzymology
  • Brain Ischemia / physiopathology
  • Cerebral Cortex / enzymology*
  • Cerebral Cortex / injuries
  • Cerebral Cortex / physiopathology
  • Cerebrovascular Circulation / physiology
  • Disease Models, Animal
  • Hyperglycemia / complications*
  • Hyperglycemia / enzymology
  • Hyperglycemia / physiopathology
  • Immunohistochemistry
  • Infarction, Middle Cerebral Artery / complications
  • Infarction, Middle Cerebral Artery / enzymology
  • Infarction, Middle Cerebral Artery / physiopathology
  • Male
  • Nerve Degeneration / enzymology
  • Nerve Degeneration / pathology
  • Nerve Degeneration / physiopathology
  • Neuroglia / enzymology
  • Neuroglia / pathology
  • Neurons / enzymology
  • Neurons / pathology
  • Nitric Oxide / metabolism
  • Nitric Oxide Synthase / metabolism*
  • Oxygen / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Superoxide Dismutase / metabolism*
  • Tyrosine / analogs & derivatives*
  • Tyrosine / metabolism*


  • Nitric Oxide
  • 3-nitrotyrosine
  • Tyrosine
  • Nitric Oxide Synthase
  • Superoxide Dismutase
  • Oxygen