Abstract |
The effects of guanabenz on several autonomic systems were observed in vagotomized, anesthetized cats with the aim of determining, in a quantitative sense, the degree to which guanabenz produces a clonidine-like central nervous system action. Guanabenz given as a single dose (50 micrograms/kg i.v.) produced a transient hypertension associated with a more sustained bradycardia and depression of centrally (hypothalamic) evoked electrodermal responses (EDR). Increasing cumulative doses of guanabenz (3-1000 micrograms/kg i.v.) also resulted in a dose-related depression of EDR amplitude, transient hypertension followed by hypotension, sustained bradycardia, and mydriasis. All responses were antagonized by pretreatment with yohimbine (0.5 mg/kg i.v.). The ED50 for depression of the centrally evoked EDR was in the range of 50-100 micrograms/kg i.v. in the non-pretreated preparations. Guanabenz (100 micrograms/kg i.v.) was shown to be devoid of significant ganglionic blocking properties. These experiments suggest that guanabenz acts like clonidine in the CNS and that an alpha 2-adrenergic inhibitory mechanism is involved in its myriad of central autonomic effects.
|
Authors | M C Koss |
Journal | European journal of pharmacology
(Eur J Pharmacol)
Vol. 90
Issue 1
Pg. 19-27
(May 20 1983)
ISSN: 0014-2999 [Print] Netherlands |
PMID | 6873176
(Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)
|
Chemical References |
- Guanidines
- Yohimbine
- Guanabenz
- Clonidine
|
Topics |
- Animals
- Blood Pressure
(drug effects)
- Cats
- Central Nervous System
(drug effects)
- Clonidine
(pharmacology)
- Dose-Response Relationship, Drug
- Electric Stimulation
- Female
- Ganglia, Sympathetic
(drug effects)
- Guanabenz
(pharmacology)
- Guanidines
(pharmacology)
- Heart Rate
(drug effects)
- Hypothalamus
(physiology)
- Male
- Peripheral Nerves
(physiology)
- Sympathetic Nervous System
(drug effects)
- Yohimbine
(pharmacology)
|