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Dexmedetomidine prevents epinephrine-induced arrhythmias through stimulation of central alpha 2 adrenoceptors in halothane-anesthetized dogs.
- Source :
-
Anesthesiology [Anesthesiology] 1991 Jul; Vol. 75 (1), pp. 113-7. - Publication Year :
- 1991
-
Abstract
- Since alpha 2-adrenergic agonists have important effects on the adrenergic system that have recently been applied to the anesthetic setting, we investigated the effect of stimulation of alpha 2 adrenoceptors on epinephrine-induced arrhythmias in halothane-anesthetized dogs. The arrhythmogenic threshold for epinephrine was determined during halothane anesthesia in the presence of dexmedetomidine, a selective alpha 2 agonist, and L-medetomidine, a stereoisomer of medetomidine that lacks alpha 2-agonist activity. Dexmedetomidine increased the arrhythmogenic threshold for epinephrine in a dose-dependent manner during halothane anesthesia. At the highest dose of dexmedetomidine, 0.5 microgram.kg-1.min-1, there was a three-fold increase in both the arrhythmogenic dose of epinephrine and the plasma epinephrine concentration that was reached at this dose. On the other hand, L-medetomidine over the same dose range did not effect the arrhythmogenic dose of epinephrine. Atipamezole, a central alpha 2 antagonist that crossed the blood-brain barrier, blocked the antiarrhythmic action of dexmedetomidine. L-659,066 a peripheral alpha 2 antagonist that does not penetrate the blood-brain barrier, did not affect the antiarrhythmic action of dexmedetomidine. Thus, dexmedetomidine's antiarrhythmic effect on epinephrine-induced arrhythmias during halothane anesthesia appears to be mediated at least in part by stimulation of central alpha 2 adrenoceptors.
- Subjects :
- Animals
Arrhythmias, Cardiac chemically induced
Blood Pressure
Dogs
Epinephrine blood
Female
Heart Rate drug effects
Male
Medetomidine
Stereoisomerism
Adrenergic alpha-Agonists pharmacology
Anesthesia, Inhalation
Arrhythmias, Cardiac prevention & control
Epinephrine antagonists & inhibitors
Halothane
Imidazoles pharmacology
Subjects
Details
- Language :
- English
- ISSN :
- 0003-3022
- Volume :
- 75
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Anesthesiology
- Publication Type :
- Academic Journal
- Accession number :
- 1676567
- Full Text :
- https://doi.org/10.1097/00000542-199107000-00018