Document Detail

Effects of endothelin upon blood pressure in normotensive rabbits and in perinephritis hypertension.
MedLine Citation:
PMID:  1325511     Owner:  NLM     Status:  MEDLINE    
AIMS: The effects of endothelin upon blood pressure were investigated in normotensive and hypertensive rabbits. METHODS: Endothelin was injected intravenously into conscious animals and blood pressure was monitored. Groups were pretreated with vehicle, calcium antagonists, indomethacin to block prostaglandin release, or NG-nitro-L-arginine methyl ester (L-NAME) to block endothelium-derived relaxing factor (EDRF) production in order to study the mechanisms of action of endothelin in normotensive and hypertensive animals. RESULTS: Intravenous endothelin caused a rapid depressor response lasting less than 1 min followed by a prolonged pressor response. Calcium antagonists attenuated this pressor response. Hypertensive animals showed a greater sensitivity to calcium antagonists than normotensives. High concentrations of calcium antagonists abolished the pressor response, revealing a more prolonged depressor response lasting up to 5 min. Indomethacin pretreatment caused an apparent dose-related increase in pressor responses in all animals. L-NAME pretreatment enhanced responses in normotensives but caused no change or a decrease in these responses in hypertensive animals. Neither calcium antagonists, indomethacin or L-NAME modified the initial depressor response to endothelin. However when given together with nifedipine infusion, which abolished the pressor response, indomethacin and L-NAME decreased the duration of the depressor response. CONCLUSIONS: In conscious rabbits extracellular calcium influx is important in mediating pressor responses to endothelin. In normotensive rabbits endothelin apparently causes release of prostaglandin and EDRF modifying responses. In hypertensive rabbits, a role for prostaglandins but not EDRF was observed in modulating responses to endothelin. Thus, the measured response to endothelin is the sum of a number of effects, the relative importance of which may be altered in pathological conditions.
C A Hamilton; Y T Huang; J L Reid
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of hypertension     Volume:  10     ISSN:  0263-6352     ISO Abbreviation:  J. Hypertens.     Publication Date:  1992 Aug 
Date Detail:
Created Date:  1992-10-08     Completed Date:  1992-10-08     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  8306882     Medline TA:  J Hypertens     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  787-94     Citation Subset:  IM    
Department of Medicine and Therapeutics, Gardiner Institute, Western Infirmary, Glasgow, UK.
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MeSH Terms
Arginine / analogs & derivatives,  pharmacology
Blood Pressure / drug effects*
Calcium / physiology
Calcium Channel Blockers / pharmacology
Endothelins / pharmacology*
Hypertension / physiopathology*
Indomethacin / pharmacology
NG-Nitroarginine Methyl Ester
Nifedipine / pharmacology
Nitric Oxide / antagonists & inhibitors
Perinephritis / physiopathology*
Prostaglandins / physiology
Time Factors
Reg. No./Substance:
0/Calcium Channel Blockers; 0/Endothelins; 0/Prostaglandins; 10102-43-9/Nitric Oxide; 21829-25-4/Nifedipine; 50903-99-6/NG-Nitroarginine Methyl Ester; 53-86-1/Indomethacin; 74-79-3/Arginine; 7440-70-2/Calcium

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

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