Document Detail

Isobolographic analysis of the interaction between fenoldopam and levodopa on arterial blood pressure of the rat.
MedLine Citation:
PMID:  10975601     Owner:  NLM     Status:  MEDLINE    
Fenoldopam (FD) and levodopa (LD) injected intravenously in rats in a noncumulative schedule induced dose-dependent reductions in mean arterial blood pressure. The doses that induced a 50% reduction in the initial control mean arterial pressure (referred as ED50) were calculated by linear regression analysis of the corresponding parallel dose-response curves and were 0.88 and 0.068 mg/kg, respectively. The interaction between the effects of FD and LD on pressure reduction was evaluated by simultaneous administration of different fixed ratios of FD and LD (16:1) and obtaining a dose-response curve. An isobolographic analysis was then performed, which showed that the experimental point for the effect of the simultaneous administration of FD and LD was significantly different from the theoretically calculated additive point, denoting supradditivity. It was concluded that the effect of the combination of FD and LD on mean blood pressure reduction was synergic and was probably due to an activation of D1 vascular receptors by both drugs, in conjunction with an activation of beta2 adrenoceptors by LD and a blocking action of FD on postsynaptic alpha1-adrenoceptors.
M Quevedo; J C Prieto; H F Miranda; G Pinardi
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of cardiovascular pharmacology     Volume:  36     ISSN:  0160-2446     ISO Abbreviation:  J. Cardiovasc. Pharmacol.     Publication Date:  2000 Sep 
Date Detail:
Created Date:  2001-01-02     Completed Date:  2001-01-02     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  7902492     Medline TA:  J Cardiovasc Pharmacol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  413-5     Citation Subset:  IM    
Programa de Farmacología Molecular y Clínica, Facultad de Medicina, Universidad de Chile, Santiago.
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MeSH Terms
Antihypertensive Agents / pharmacology*
Antiparkinson Agents / pharmacology*
Blood Pressure / drug effects*
Drug Synergism
Fenoldopam / pharmacology*
Levodopa / pharmacology*
Rats, Sprague-Dawley
Reg. No./Substance:
0/Antihypertensive Agents; 0/Antiparkinson Agents; 0/Levodopa; 67227-56-9/Fenoldopam

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

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