Document Detail

Effects of clonidine and yohimbine on a C-fibre-evoked blood pressure reflex in the rat.
MedLine Citation:
PMID:  3179615     Owner:  NLM     Status:  MEDLINE    
1. The involvement of alpha 2-adrenoceptors in a capsaicin-induced depressor reflex in the rat has been investigated. 2. The reflex fall in blood pressure following an intra-arterial injection of capsaicin was partially blocked by an intrathecal infusion of clonidine (1 microgram) at the spinal cord level L4-L5, an effect which was abolished by the prior intrathecal infusion of yohimbine (5 micrograms). 3. Clonidine (1 microgram) given intracisternally blocked the depressor reflex almost completely; however, it also produced a gradual, prolonged fall in mean carotid pressure. 4. Yohimbine (20 micrograms) given intracisternally did not change mean blood pressure but had a dual effect on the depressor reflex in response to the capsaicin injection: a short period of enhanced reflex response was followed by a long lasting inhibition of the response. 5. It was concluded that alpha 2-adrenoceptors in the spinal cord inhibit the capsaicin-evoked depressor reflex and that pre- and postsynaptic alpha 2-adrenoceptors in the brain stem modulate this reflex.
J Donnerer; Z Yan; F Lembeck
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  British journal of pharmacology     Volume:  94     ISSN:  0007-1188     ISO Abbreviation:  Br. J. Pharmacol.     Publication Date:  1988 Jul 
Date Detail:
Created Date:  1988-12-21     Completed Date:  1988-12-21     Revised Date:  2009-11-18    
Medline Journal Info:
Nlm Unique ID:  7502536     Medline TA:  Br J Pharmacol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  848-52     Citation Subset:  IM    
Department of Experimental and Clinical Pharmacology, University of Graz, Austria.
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MeSH Terms
Blood Pressure / drug effects*
Capsaicin / antagonists & inhibitors,  pharmacology*
Cisterna Magna
Clonidine / administration & dosage,  pharmacology*
Injections, Spinal
Nerve Fibers / drug effects*
Rats, Inbred Strains
Reflex / drug effects
Yohimbine / administration & dosage,  pharmacology*
Reg. No./Substance:
146-48-5/Yohimbine; 404-86-4/Capsaicin; 4205-90-7/Clonidine

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

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