Related Experiment Videos
Effect of different calcium antagonists on transcapillary fluid shift
J P Valentin1, J Ribstein, J M Halimi
1Department of Medicine, Centre Hospitalier Universitaire, Montpellier, France.
American Journal of Hypertension
|June 1, 1990
Summary
Calcium channel blockers like nicardipine can cause peripheral edema by affecting fluid distribution. This study in rats suggests nicardipine, unlike diltiazem, increases protein leakage into muscles, potentially explaining this side effect.
Area of Science:
- Pharmacology
- Cardiovascular Physiology
Background:
- Calcium antagonists, particularly dihydropyridines, are frequently associated with peripheral edema.
- This edema occurs without evidence of systemic fluid retention, suggesting altered fluid distribution.
Purpose of the Study:
- To investigate the impact of calcium antagonists on extracellular fluid volume partitioning.
- To compare the effects of nicardipine and diltiazem on hematocrit and plasma protein concentration in vivo.
Main Methods:
- Anephric anesthetized rats were infused with nicardipine, diltiazem, or vehicle.
- Hematocrit and plasma protein concentration were measured.
- Evans blue dye was used to assess albumin extravasation in various tissues.
Main Results:
- Nicardipine, but not diltiazem, significantly increased hematocrit and plasma protein concentration.
- Nicardipine significantly increased albumin extravasation into skeletal and cardiac muscle tissues.
- Both drugs decreased blood pressure in a dose-dependent manner.
Conclusions:
- Nicardipine and diltiazem, even at equihypotensive doses, exhibit differential effects on extracellular fluid partitioning.
- Nicardipine's ability to increase protein extravasation in muscle may contribute to the peripheral edema observed in patients.
- These findings highlight distinct mechanisms of action for different classes of calcium antagonists regarding fluid balance.