J Korean Neurol Assoc.  1995 Jun;13(2):177-186.

Ischemia-Induced Release of (3H) norepinephrine from Rat Cerebral Cortex Slices

• Lee SH
• Shin BS
• Seo MW
• Kim YH
• Kim KW

Abstract

OBJECTIVE
& BACKGROUND: It has been shown that cerebral ischemia alters brain monoamine metabolism. In an attempt to elucidate the. Mechanism for ischen-iiainduced release of neurotransmitters in vitro, we examined the ischemia-induced release of (3H) norepinephrine (NE) from cerebral cortex of the rat.
RESULTS
Ischemia, deprivation of oxygen and glucose, induced significant (about 12% of total tissue content) release of (3H)NE from cerebral cortex in vitro. This ischemia-induced release of (3H)NE from cerebral cortex was significantly attenuated by 1 mM TTX (tetrodotoxin), 1. 2 mM Mg2+, 10 mM MK-801, 10 mM ketamine, NMDA receptor antagonist, 30 mM DNQX, a kainate/AMPA receptor antagonist, or a 30 mM carbetapentane, an inhibitor of glutarnate release Dantrolene(30 mM) and ryanodine (100 nM), inhibitors of intraceuular Ca2+ release, flunarizine(5 mM) and w-conotoxin (100 nM), inhibitors of N-type Ca2+ channels, significantly attenuated the ischeniiainduced release of (3H)NF, but verapamil (5mM), an inhibitor of L-type Ca2+ channels, did not. Nisoxetine(100 nM), a relative NE transporter blocker, significantly inhibited the ischemia-induced release of (3H) NE. Removal of Ca2+ from the incubation media potently increased ischemia-induced (3H)NE release.
CONCLUSION
These results suggest that ischemia-evoked release of norepienphrine was caused by release of glutamate via activation of NMDA and non-NMDA receptors, and that Ca2+-dependent and -independent release processes are underlying in this phenomenon.

Keyword

Cerebral ischemia; glutamate; norepinephrine; Ca2+; cerebral cortex

MeSH Terms

Animals
Brain
Brain Ischemia
Cerebral Cortex*
Dizocilpine Maleate
Glucose
Glutamic Acid
Ischemia
Ketamine
Metabolism
N-Methylaspartate
Neurotransmitter Agents
Norepinephrine*
Oxygen
Rats*
Ryanodine
Verapamil
Dizocilpine Maleate
Glucose
Glutamic Acid
Ketamine
N-Methylaspartate
Neurotransmitter Agents
Norepinephrine
Oxygen
Ryanodine
Verapamil