Pharmacological profiles of benzodiazepinergic hypnotics and correlations with receptor subtypes

Mitsuru Yasui, Akira Kato, Toshiyuki Kanemasa, Shunji Murata, Kohei Nishitomi, Katsumi Koike, Nobuyuki Tai, Shunji Shinohara, Miwa Tokumura, Masahito Horiuchi, Kohji Abe

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


We examined the behavioral pharmacological properties of six benzodiazepine (ω) receptor ligands including brotizoram, nitrazepam, quazepam, rilmazafone, zolpidem and zopiclone and the binding of these drugs with ω receptor subtypes. Behavioral tests were performed at the time of the maximal effects induced by each drug following its oral administration to mice. All of these drugs dose-dependently induced impairment of motor coordination as rotarod performance and potentiation of thiopental-induced anesthesia as hypnotic effect. The hypnotic effects of rilmazafone, whose major metabolites were bound to both ω1 and ω2 receptors with high affinity, and ω1 selective quazepam were about 20 times more effective than the induction of motor impairments when compared with ED 50 values. However, there was no difference between the ED 50 values of ω1 selective zolpidem alone in these two tests. An antianxiety efficacy of zolpidem was relatively weak unlike that of other drugs in the elevated plus-maze. It has been reported that ω1, but not ω1, receptors are associated with motor impairment and anxiolytic effect. The weak anxiolytic effect of zolpidem supports the previous hypothesis. However, the strong motor incoordination of zolpidem suggests that not only ω2 but also ω1 receptors are related to motor impairment unlike the previous hypothesis.

Original languageEnglish
Pages (from-to)143-151
Number of pages9
JournalJapanese Journal of Neuropsychopharmacology
Issue number3
Publication statusPublished - Jul 1 2005
Externally publishedYes


  • Benzodiazepine receptor
  • Hypnotic effect
  • Motor incoordination
  • ω
  • ω

ASJC Scopus subject areas

  • Clinical Psychology
  • Pharmacology
  • Psychiatry and Mental health
  • Pharmacology (medical)


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