Document Detail

Effects of isradipine on plasma renin activity in sodium-loaded and -depleted conscious rabbits.
MedLine Citation:
PMID:  1380591     Owner:  NLM     Status:  MEDLINE    
The antihypertensive effect of calcium antagonists is altered little by high salt intake or concomitant diuretic treatment. We therefore investigated whether modest changes in the salt balance might alter the acute response of the renin-angiotensin system to the calcium antagonist isradipine in conscious rabbits. Mongrel rabbits with indwelling arterial and venous catheters were pretreated with either a single subcutaneous injection of 20 mg/kg furosemide 24 h before the experiment [sodium depletion (SD)] or the addition of 0.45% NaCl to the drinking water, which was available ad libitum for 24 h [sodium loading (SL)]. Compared with SL, SD pretreatment modestly increased plasma renin activity and lowered body weight; mean arterial pressure and heart rate were unchanged. Isradipine (10, 30, and 100 micrograms/kg) infused into the femoral vein catheter decreased blood pressure and increased heart rate similarly in both groups. Increases in plasma renin activity plotted as a function of the decreases in blood pressure showed a significantly steeper slope in SD than in SL animals. When blood pressure started to recover 15 min after the end of drug infusion, plasma renin activity decreased in SL animals only. Therefore, SL or SD strongly influences the responsiveness of the renin-angiotensin system to calcium antagonists, and this may be one reason why high salt intake does not diminish the antihypertensive effect of calcium antagonists and a calcium antagonist/diuretic combination may not yield optimal therapeutic results.
R P Hof; K Umemura; J P Evenou; A Hof; P C Rüegg
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of cardiovascular pharmacology     Volume:  19     ISSN:  0160-2446     ISO Abbreviation:  J. Cardiovasc. Pharmacol.     Publication Date:  1992 Apr 
Date Detail:
Created Date:  1992-09-18     Completed Date:  1992-09-18     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:  503-7     Citation Subset:  IM    
Preclinical Research, Sandoz Pharma Ltd., Basel, Switzerland.
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MeSH Terms
Analysis of Variance
Antihypertensive Agents / pharmacology*
Blood Pressure / drug effects
Body Weight / drug effects
Calcium Channel Blockers / pharmacology*
Dihydropyridines / pharmacology*
Furosemide / pharmacology
Heart Rate / drug effects
Renin / blood*
Sodium / metabolism*
Sodium, Dietary / administration & dosage
Reg. No./Substance:
0/Antihypertensive Agents; 0/Calcium Channel Blockers; 0/Dihydropyridines; 0/Sodium, Dietary; 54-31-9/Furosemide; 7440-23-5/Sodium; 75695-93-1/Isradipine; EC

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

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