Calcium channel blockers (CCB), calcium channel antagonists or calcium antagonists are a group of medications that disrupt the movement of calcium through calcium channels. Calcium channel blockers are used as antihypertensive drugs, i.e., as medications to decrease blood pressure in patients with hypertension. CCBs are particularly effective against large vessel stiffness, one of the common causes of elevated systolic blood pressure in elderly patients. Calcium channel blockers are also frequently used to alter heart rate, to prevent peripheral and cerebral vasospasm, and to reduce chest pain caused by angina pectoris.
Verapamil, sold under various trade names, is a calcium channel blocker medication used for the treatment of high blood pressure, angina, and supraventricular tachycardia. It may also be used for the prevention of migraines and cluster headaches. It is given by mouth or by injection into a vein.
Unlike the action potential in skeletal muscle cells, the cardiac action potential is not initiated by nervous activity. Instead, it arises from a group of specialized cells known as pacemaker cells, that have automatic action potential generation capability. In healthy hearts, these cells form the cardiac pacemaker and are found in the sinoatrial node in the right atrium. They produce roughly 60–100 action potentials every minute. The action potential passes along the cell membrane causing the cell to contract, therefore the activity of the sinoatrial node results in a resting heart rate of roughly 60–100 beats per minute. All cardiac muscle cells are electrically linked to one another, by intercalated discs which allow the action potential to pass from one cell to the next. This means that all atrial cells can contract together, and then all ventricular cells.
A calcium channel is an ion channel which shows selective permeability to calcium ions. It is sometimes synonymous with voltage-gated calcium channel, which are a type of calcium channel regulated by changes in membrane potential. Some calcium channels are regulated by the binding of a ligand. Other calcium channels can also be regulated by both voltage and ligands to provide precise control over ion flow. Some cation channels allow calcium as well as other cations to pass through the membrane.
Nicorandil is a vasodilator drug used to treat angina.
1,4-Dihydropyridine (DHP) is an organic compound with the formula CH2(CH=CH)2NH. The parent compound is uncommon, but derivatives of 1,4-dihydropyridine are important commercially and biologically. The pervasive cofactors NADH and NADPH are derivatives of 1,4-dihydropyridine. 1,4-Dihydropyridine-based drugs are L-type calcium channel blockers, used in the treatment of hypertension. 1,2-Dihydropyridines are also known.
Calcicludine (CaC) is a protein toxin from the venom of the green mamba that inhibits high-voltage-activated calcium channels, especially L-type calcium channels.
Tetany or tetanic seizure is a medical sign consisting of the involuntary contraction of muscles, which may be caused by disorders that increase the action potential frequency of muscle cells or of the nerves that innervate them.
TRPM is a family of transient receptor potential ion channels (M standing for wikt:melastatin). Functional TRPM channels are believed to form tetramers. The TRPM family consists of eight different channels, TRPM1–TRPM8.
N-type calcium channels also called Cav2.2 channels are voltage gated calcium channels that are localized primarily on the nerve terminals and dendrites as well as neuroendocrine cells. The calcium N-channel consists of several subunits: the primary subunit α1B and the auxiliary subunits α2δ and β. The α1B subunit forms the pore through which the calcium enters and helps to determine most of the channel's properties. These channels play an important role in the neurotransmission during development. In the adult nervous system, N-type calcium channels are critically involved in the release of neurotransmitters, and in pain pathways. N-type calcium channels are the target of ziconotide, the drug prescribed to relieve intractable cancer pain. There are many known N-type calcium channel blockers that function to inhibit channel activity, although the most notable blockers are ω-conotoxins.
SK3 also known as KCa2.3 is a protein that in humans is encoded by the KCNN3 gene.
Cav1.4 also known as the calcium channel, voltage-dependent, L type, alpha 1F subunit (CACNA1F), is a human gene.
Chloride channel accessory 1 is a protein that in humans is encoded by the CLCA1 gene.
Voltage-dependent L-type calcium channel subunit beta-4 is a protein that in humans is encoded by the CACNB4 gene.
Calcium channel, voltage-dependent, L type, alpha 1D subunit is a protein that in humans is encoded by the CACNA1D gene. Cav1.3 channels belong to the Cav1 family, which form L-type calcium currents and are sensitive to selective inhibition by dihydropyridines (DHP).
Devapamil is a calcium channel blocker. It is also known as desmethoxyverapamil, which is a phenylalkylamine (PAA) derivative. Devapamil not only inhibits by blocking the calcium gated channels, but also by depolarizing the membrane during the sodium-potassium exchanges.
AH-1058 is a lipophilic antiarrhythmic calcium channel blocker synthesized by the Pharmaceutical Research Laboratories of Ajinomoto Co., Inc in Kawasaki, Japan. It is derived from cyproheptadine, a compound with known antiserotonic, antihistaminic and calcium channel blocking properties. The IUPAC name of AH-1058 is: 4-(5H-dibenzo[a,d]cyclohepten-5-ylidene)-1-[E-3-(3-methoxy-2-nitro) phenyl-2-propenyl]piperidine hydrochloride.
AZD1305 is an experimental drug candidate that is under investigation for the management and reversal of cardiac arrhythmias, specifically atrial fibrillation and flutter. In vitro studies have shown that this combined-ion channel blocker inhibits rapidly the activating delayed-rectifier potassium current (IKr), L-type calcium current, and inward sodium current (INa).
The Calcium-Dependent Chloride Channel (Ca-ClC) proteins (or calcium-activated chloride channels, are heterogeneous groups of ligand-gated ion channels for chloride that have been identified in many epithelial and endothelial cell types as well as in smooth muscle cells. They include proteins from several structurally different families: chloride channel accessory, bestrophin, and calcium-dependent chloride channel anoctamin channels ANO1 is highly expressed in human gastrointestinal interstitial cells of Cajal, which are proteins which serve as intestinal pacemakers for peristalsis. In addition to their role as chloride channels some CLCA proteins function as adhesion molecules and may also have roles as tumour suppressors. These eukaryotic proteins are "required for normal electrolyte and fluid secretion, olfactory perception, and neuronal and smooth muscle excitability" in animals. Members of the Ca-CIC family are generally 600 to 1000 amino acyl residues in length and exhibit 7 to 10 transmembrane segments.
Antony Giuseppe Galione is a British pharmacologist. He is a professor and Wellcome Trust senior investigator in the Department of Pharmacology at the University of Oxford.
