Document Detail


Hemodynamic and metabolic effects of flunarizine in experimental subarachnoid hemorrhage in dogs.
MedLine Citation:
PMID:  8446977     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND AND PURPOSE: Cerebral blood flow and oxygen metabolism were measured and a cerebral angiography was performed in dogs with experimental subarachnoid hemorrhage to assess the relation between arterial narrowing (vasospasm) and the fall of blood flow. Cerebral blood volume and the cerebrovascular CO2 reactivity were also measured to estimate the cerebrovascular reserve. Several groups of dogs were treated with flunarizine in different regimens to assess its possible therapeutic effect. METHODS: The experiments were performed in the three-hemorrhage canine model for subarachnoid hemorrhage. Cerebral blood flow and cerebral oxygen metabolism were measured in anesthetized (nitrous oxide) dogs using positron emission tomography in combination with the 15O steady-state method. Basilar artery diameter was evaluated by digital subtraction angiography. RESULTS: In normal dogs, cerebral blood flow, oxygen consumption, and oxygen extraction ratio were 46.4 +/- 9.0 ml/100 ml per minute, 3.65 +/- 0.76 ml/100 ml per minute, and 39.9 +/- 3.4%, respectively; basilar artery diameter was 1.33 +/- 0.25 mm. Repeated subarachnoid blood injection (3 x 5 ml) reduced basilar artery diameter to < 20% of normal (p < 0.01). Cerebral blood flow was reduced by only 25% (p < 0.001); oxygen consumption was preserved at a low normal level by a 29% compensatory increase of the oxygen extraction (p < 0.001). Cerebral blood volume and cerebrovascular CO2 reactivity remained nearly normal. Early (after the first blood injection) peroral treatment with flunarizine (0.5 mg/kg daily) resulted in less severe basilar artery narrowing (56% of normal; p < 0.05 versus untreated). However, this treatment had no effect on cerebral blood flow, blood volume, oxygen consumption, and extraction. CONCLUSIONS: The observed fall of cerebral blood flow in experimental subarachnoid hemorrhage is not related to arterial narrowing but to an increased cerebrovascular resistance at the level of the small parenchymal vessels, and the latter, in contrast to arterial narrowing, is unaffected by flunarizine.
Authors:
G De Ley; W Eechaute; K Strijckmans; P Goethals; I Lemahieu; E Van de Velde; J Weyne
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Stroke; a journal of cerebral circulation     Volume:  24     ISSN:  0039-2499     ISO Abbreviation:  Stroke     Publication Date:  1993 Mar 
Date Detail:
Created Date:  1993-04-02     Completed Date:  1993-04-02     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  0235266     Medline TA:  Stroke     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  400-5; discussion 405-6     Citation Subset:  IM    
Affiliation:
Laboratory of Normal and Pathological Physiology, University of Gent, Belgium.
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MeSH Terms
Descriptor/Qualifier:
Animals
Basilar Artery / drug effects*
Brain / blood supply*
Cerebral Arteries / drug effects
Constriction, Pathologic / drug therapy
Disease Models, Animal
Dogs
Flunarizine / therapeutic use*
Oxygen Consumption / drug effects
Regional Blood Flow / drug effects
Subarachnoid Hemorrhage / drug therapy*
Tomography, X-Ray Computed
Chemical
Reg. No./Substance:
52468-60-7/Flunarizine

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


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