Document Detail

Increase in plasma renin activity evoked by fenoldopam in dogs is directly mediated by dopamine1 receptor stimulation.
MedLine Citation:
PMID:  2472522     Owner:  NLM     Status:  MEDLINE    
In anesthetized dogs, a 15-min intravenous (i.v.) infusion of fenoldopam (2.0 micrograms/kg/min) produced a decrease in mean aortic blood pressure (MAP) and an increase in renal blood flow (RBF) and plasma renin activity (PRA). The hypotensive effect attained a maximum within 5 min and then waned by approximately 30% at the end of fenoldopam administration. The development of this "tolerance" phenomenon was prevented by enalapril or saralasin. The hypotension and the increase in PRA were not modified by either propranolol or chlorisondamine but were inhibited by SCH 23390, a DA1 antagonist. Fenoldopam (0.1 microgram/kg/min for 15 min) infused into the left renal artery (i.a.) in intact or ganglion-blocked dogs did not change MAP but increased PRA. This effect was antagonized by SCH 23390. In ganglion-blocked preparations in which an apparently maximal renal vasodilatation had been achieved by an i.a. acetylcholine, i.a. fenoldopam produced an increase in PRA which was again blocked by SCH 23390. In uninephrectomized dogs, blockade of alpha- and beta-adrenoceptors or inhibition of renal baroreceptor and macula densa mechanisms of renin release failed to prevent the fenoldopam-induced increase in PRA. In conclusion, the release of renin by fenoldopam is responsible for the development of tolerance to the hypotensive effects of fenoldopam. Furthermore, because the increase in PRA was blocked by SCH 23390 and occurred in the absence of either operational systemic or intrarenal regulatory mechanisms, we propose that it is mediated by stimulation of specific dopamine (DA1) receptors on the juxtaglomerular (JG) cells.
F Montier; P Katchadourian; J Pratz; I Cavero
Publication Detail:
Type:  In Vitro; Journal Article    
Journal Detail:
Title:  Journal of cardiovascular pharmacology     Volume:  13     ISSN:  0160-2446     ISO Abbreviation:  J. Cardiovasc. Pharmacol.     Publication Date:  1989 May 
Date Detail:
Created Date:  1989-08-09     Completed Date:  1989-08-09     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  7902492     Medline TA:  J Cardiovasc Pharmacol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  739-47     Citation Subset:  IM    
Rhône-Poulenc Santé, Centre de Recherche de Vitry, Vitry-sur-Seine, France.
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MeSH Terms
Acetylcholine / pharmacology
Benzazepines / pharmacology*
Blood Pressure / drug effects
Chlorisondamine / pharmacology
Enalapril / pharmacology
Heart Rate / drug effects
Indomethacin / pharmacology
Injections, Intravenous
Prazosin / pharmacology
Propranolol / pharmacology
Receptors, Dopamine / drug effects*
Renal Circulation / drug effects
Renin / blood*
Stimulation, Chemical
Reg. No./Substance:
0/Benzazepines; 0/Receptors, Dopamine; 19216-56-9/Prazosin; 51-84-3/Acetylcholine; 525-66-6/Propranolol; 53-86-1/Indomethacin; 67227-56-9/Fenoldopam; 75847-73-3/Enalapril; 7701-62-4/Chlorisondamine; EC

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