Related Experiment Videos
Nitrendipine: effects on vascular responses and myocardial binding
The American Journal of Physiology
|November 1, 1984
Summary
Nitrendipine binding to cardiac and vascular tissues is rapid and saturable. This calcium channel blocker dose-dependently reduces cardiac and coronary artery contractility, impacting calcium responses.
Area of Science:
- Pharmacology
- Cardiovascular Physiology
Background:
- Nitrendipine is a dihydropyridine calcium channel blocker.
- Understanding its binding characteristics and effects on contractility is crucial for cardiovascular research.
Purpose of the Study:
- To characterize [3H]nitrendipine binding in various species' myocardial and coronary vasculature tissues.
- To investigate nitrendipine's impact on contractile responses in isolated cardiac muscle and coronary arteries.
Main Methods:
- Radioligand binding assays using [3H]nitrendipine.
- Measurement of contractile responses in isolated feline cardiac muscle and canine coronary arteries.
- Dose-response studies and assessment of effects on calcium-induced contractions.
Main Results:
- [3H]nitrendipine binding was rapid, saturable, and reversible across species and tissues.
- Feline myocardium showed a single binding site (KD 1.94 nM); canine myocardium suggested two sites (high-affinity KD 0.17 nM).
- Nitrendipine dose-dependently reduced contractility in feline cardiac muscle (ED50 0.20 µM) and canine coronary arteries (ED50 1.6-6.3 nM), blunting calcium responses.
Conclusions:
- Nitrendipine exhibits specific binding properties in cardiac and vascular tissues.
- The drug effectively inhibits cardiac and coronary artery contractility, with concentrations for binding and effect being comparable in some tissues.