Alpha 2-adrenoceptor agonist, dexmedetomidine, protects against kainic acid-induced convulsions and neuronal damage

Brain Res. 1995 Sep 25;693(1-2):217-24. doi: 10.1016/0006-8993(95)00744-b.

Abstract

Kainic acid (KA)-induced convulsions are accompanied by histopathological changes that are most prominent in the temporal lobe structures. In the present study, we investigated whether a selective alpha2-adrenoceptor agonist, dexmedetomidine could attenuate KA-induced epileptic convulsions and subsequent neuronal damage in the rat hippocampus. Rats were pretreated 30 min before KA injection (9 mg/kg, i.p.) with dexmedetomidine (3 micrograms/kg, s.c.). The behavior of animals was observed for at least 3 h. Dexmedetomidine suppressed the development (p < 0.001), generalization (p < 0.05) and severity (p < 0.01) of convulsions. In addition, histological analysis revealed that dexmedetomidine-treated animals without convulsions or with only partial convulsions had no neuronal damage in the principal cell layers of the hippocampus. A selective alpha2-antagonist, atipamezole (1 mg/kg, s.c.) potentiated KA-induced convulsions and increased the mortality in status epilepticus. In conclusion, the present study demonstrated that dexmedetomidine, in addition to possessing anticonvulsant properties, has a neuroprotective effect in the KA model of status epilepticus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic alpha-Agonists / pharmacology*
  • Adrenergic alpha-Antagonists / pharmacology
  • Animals
  • Anticonvulsants / pharmacology
  • Disease Models, Animal
  • Hippocampus / cytology
  • Hippocampus / physiopathology
  • Histocytochemistry
  • Imidazoles / pharmacology*
  • Kainic Acid / pharmacology
  • Male
  • Medetomidine
  • Nerve Degeneration / drug effects
  • Neurons / pathology*
  • Rats
  • Rats, Wistar
  • Seizures / chemically induced*
  • Status Epilepticus / drug therapy
  • Vigabatrin
  • gamma-Aminobutyric Acid / analogs & derivatives
  • gamma-Aminobutyric Acid / pharmacology

Substances

  • Adrenergic alpha-Agonists
  • Adrenergic alpha-Antagonists
  • Anticonvulsants
  • Imidazoles
  • atipamezole
  • gamma-Aminobutyric Acid
  • Vigabatrin
  • Medetomidine
  • Kainic Acid