What are calcium channels?
Calcium channels are openings in the membrane of electrically excitable cells such as nerve cells and muscle cells. They lead directly from the inside to the outside of a cell and regulate the amount of calcium that enters and leaves a cell. The concentration of calcium is normally much higher outside the cell, but when triggered by certain stimuli, the cell membrane depolarises and calcium channels open to allow an influx of calcium into the cell, which results in different reactions, depending on the type of cells. In smooth muscle cells, such as are found in the blood vessels walls, and in cardiac muscle of the heart, the response is for the cells to contract. This causes narrowing of the blood vessels and increases the force and rate of contraction of the heart, which increase blood pressure.
How calcium channels blockers work
Calcium channels blockers prevent the entry of calcium into smooth muscle cells, which inhibits contraction of these cells allowing them to widen and dilate, a process called vasodilation. The result of vasodilation is to reduce resistance in peripheral blood vessels, which reduces blood pressure and this in turn reduces the force needed for the heart to pump blood around the body and thereby reduces its oxygen requirement. The overall effect of calcium channels blockers helps reduce symptoms of cardiovascular disease, such as angina.
calcium channels blockers for cardiovascular disease and hypertension
Calcium channel blockers are used to treat hypertension and reduce symptoms of cardiovascular disease, such as angina.
The Calcium channel blockers available include nifedipine, amlodipine, diltiazem, felodipine and verapamil