Document Detail

Effects of low doses of clonidine in the monkey cranial circulation.
MedLine Citation:
PMID:  7202484     Owner:  NLM     Status:  MEDLINE    
Migraine therapy using low doses of clonidine has been based on the proposal that clonidine directly inhibits vascular smooth muscle reactivity. In anaesthetized monkeys in which internal and external carotid vascular resistances were measured, the only significant effects of clonidine administered acutely (0.5 and 2 microgram x kg-1 i.v.) or chronically (2 microgram x kg-1 i.m. daily for 7 days) on cranial vascular responses to the constrictors noradrenaline and 5-hydroxytryptamine, and the dilators histamine, prostaglandin E1 and bradykinin, were small potentiations of some of the responses. Acute clonidine initially increased blood pressure and constricted the cranial vasculature, then induced hypotension without involvement of the cranial circulation. It also decreased the external carotid vasoconstrictor response to low frequency cervical sympathetic nerve stimulation. The low chronic dose of clonidine had no hypotensive effect. The pressor response to common carotid occlusion was inhibited by both acute and chronic clonidine. These experiments thus provide no evidence that clonidine inhibits cranial vascular reactivity at doses equivalent to those used in migraine.
E J Mylecharane; J W Duckworth; G D Lord; J W Lance
Related Documents :
2170054 - Synergistic hypotensive effect of vasoactive intestinal polypeptide and alpha-blockade ...
23745044 - An investigation of the influence of cell topography on epithelial mechanical stresses ...
343894 - New drugs in hypertension.
6139984 - Relaxation of rabbit cerebral arteries in vitro by clonidine. evidence of h2-receptor m...
3734514 - Digital pressure and flow measurement upon local cooling in raynaud's disease. effect o...
8911354 - Antireflux nipples or afferent tubular segments in 70 patients with ileal low pressure ...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  European journal of pharmacology     Volume:  68     ISSN:  0014-2999     ISO Abbreviation:  Eur. J. Pharmacol.     Publication Date:  1980 Nov 
Date Detail:
Created Date:  1981-05-28     Completed Date:  1981-05-28     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  1254354     Medline TA:  Eur J Pharmacol     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  163-73     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Blood Pressure / drug effects
Cerebrovascular Circulation / drug effects*
Clonidine / administration & dosage,  pharmacology*
Dose-Response Relationship, Drug
Histamine / pharmacology
Macaca nemestrina
Migraine Disorders / drug therapy
Norepinephrine / pharmacology
Sympathetic Nervous System / drug effects
Vascular Resistance / drug effects
Reg. No./Substance:
4205-90-7/Clonidine; 51-41-2/Norepinephrine; 51-45-6/Histamine

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

Previous Document:  Further studies on the actions of salicylates on nerve membranes.
Next Document:  Lack of effect of choline and narcotic antagonists upon apomorphine discrimination.