Document Detail


The action of clonidine on the baroreflex control of heart rate in conscious animals and man, and on single aortic baroreceptor discharge in the rabbit.
MedLine Citation:
PMID:  1156024     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Changes in mean arterial pressure (M.A.P.) have been produced in conscious rabbits by inflation of balloon cuffs previously implanted round the inferior vena cave and aorta; Sigmoid stimulus/response curves (M.A.P./Heart Period, H.P.) were constructed. Clonidine caused a striking dose dependent increase in gain of the reflex arc in both normal rabbits and rabbits with renal hypertension. The largest effect was upon vagal motorneurones but a similar but smaller effect was present in vagotomised animals. Similar changes in the baro-reflex arc were produced by injection of very much smaller doses of clonidine into the lateral cerebral ventricle. Recordings made from single aortic baroreceptor fibres in anaesthetised rabbits showed again a dose dependeent sensitisation. These results suggest that the bradycardia caused by clonidine is largely mediated via an action in the brain on the baroreflex arc, with an additional action on the baroreceptors themselves. Preliminary results in normal man show a similar increase in the gain of this reflex after intravenous clonidine (150 mug).
Authors:
P Sleight; M J West; P I Korner; J R Oliver; J P Chalmers; J L Robinson
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Archives internationales de pharmacodynamie et de thérapie     Volume:  214     ISSN:  0003-9780     ISO Abbreviation:  Arch Int Pharmacodyn Ther     Publication Date:  1975 Mar 
Date Detail:
Created Date:  1975-11-08     Completed Date:  1975-11-08     Revised Date:  2012-01-12    
Medline Journal Info:
Nlm Unique ID:  0405353     Medline TA:  Arch Int Pharmacodyn Ther     Country:  BELGIUM    
Other Details:
Languages:  eng     Pagination:  4-11     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Animals
Aorta / drug effects*,  innervation
Blood Pressure / drug effects
Clonidine / administration & dosage,  pharmacology*
Female
Heart Rate / drug effects*
Heart Ventricles
Humans
Injections
Male
Pressoreceptors / physiology*
Rabbits
Reflex / drug effects*
Chemical
Reg. No./Substance:
4205-90-7/Clonidine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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