Antinociceptive effects of the hydrophilic α2-adrenoceptor agonist ST-91 in different test circumstances after intrathecal administration to Wistar rats

Gyöngyi Horváth, Ildikó Dobos, Péter Liszli, Walter Klimscha, Margit Szikszay, György Benedek

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The antinociceptive and motor effects of the hydrophilic α2-adrenoceptor agonist ST-91 were studied after intrathecal administration to male Wistar rats in different heat-pain tests and different test settings. Intrathecal administration of ST-91 caused a dose-dependent increase in hind paw licking latency in the hot-plate test, while in contrast with morphine it had a much lower efficacy in the tail-flick test in freely moving conditions. Sprague-Dawley rats gave similar results to those for Wistar rats in this setting. However, when the tail-flick test was performed under chronic restraint conditions (after a 1-h restraining period), the compound caused a significant antinociception. No signs of motor impairment and no changes in electromyographic activity were detected after ST-91 administration. The results indicate a characteristic analgesic profile for ST-91. In the interpretation of ST-91 data, consideration should be paid both to test model differences and to test conditions.

Original languageEnglish
Pages (from-to)561-568
Number of pages8
JournalPharmacological Research
Issue number6
Publication statusPublished - Jun 1997



  • Hot-plate
  • Restraint
  • ST-91
  • Spinal
  • Tail-flick
  • α-adrenoceptor

ASJC Scopus subject areas

  • Pharmacology

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