Dexmedetomidine-induced decrease in cerebral blood flow is attenuated by verapamil in rats: a laser Doppler study

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This study was performed to examine the changes in local cortical blood flow (CoBF) after simultaneous administration of an alpha2 adrenergic agonist (dexmedetomidine) and a calcium channel antagonist (verapamil) to urethane-anaesthetized rats. Dexmedetomidine (100 μg · kg-1) given intraperitoneally alone resulted in decreases in mean arterial blood pressure (MABP) (F[27,140] = 3.43;P < 0.01) and CoBF (F[27,140] = 4.22; P < 0.01), whereas the heart rate (HR) was increased (F[27.140] = 2.33; P< 0.01). Verapamil (2.5 mg· kg-1) given subcutaneously reduced the MABP (F[27,140]) =3.41; P < 0.01), but the HR and CoBF were not changed. Combined administration of the drugs decreased MA PB (F[27,140]) = 5.37; P < 0.01), with no changes in CoBF and HR. The present data indicate that the calcium channel antagonist verapamil did not potentiate the haemodynamic effects of dexmédétomidine in rats, but rather attenuated the effect of dexmédétomidine on CoBF. This favourable interaction suggests a potential therapeutic role of these agents in maintaining cardiovascular stability during surgical interventions.

Original languageEnglish
Pages (from-to)748-754
Number of pages7
JournalCanadian Journal of Anaesthesia
Issue number8
Publication statusPublished - Aug 1 1993



  • blood pressure
  • brain: blood flow
  • heart rate
  • measurement techniques: laser Doppler flowmetry
  • pharmacology: verapamil
  • sympathetic nervous system: alpha-adrenergic agonist, dexmedetomidine

ASJC Scopus subject areas

  • Anesthesiology and Pain Medicine

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