Search results
Results from the WOW.Com Content Network
Muscarinic acetylcholine receptors (mAChRs) are acetylcholine receptors that form G protein-coupled receptor complexes in the cell membranes of certain neurons [1] and other cells. They play several roles, including acting as the main end-receptor stimulated by acetylcholine released from postganglionic fibers .
Nicotinic acetylcholine receptors, or nAChRs, are receptor polypeptides that respond to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs such as the agonist nicotine . They are found in the central and peripheral nervous system, muscle, and many other tissues of many organisms.
The nicotine ACh receptor is also a Na +, K + and Ca 2+ ion channel. Muscarinic acetylcholine receptors (mAChR, also known as "metabotropic" acetylcholine receptors) are particularly responsive to muscarine. Nicotinic and muscarinic are two main kinds of "cholinergic" receptors.
Chemical structure of acetylcholine. Cholinergic blocking drugs are a group of drugs that block the action of acetylcholine (ACh), a neurotransmitter, in synapses of the cholinergic nervous system. [1] They block acetylcholine from binding to cholinergic receptors, namely the nicotinic and muscarinic receptors.
A parasympathomimetic drug, sometimes called a cholinomimetic drug [1] or cholinergic receptor stimulating agent, [2] is a substance that stimulates the parasympathetic nervous system (PSNS). [ 3 ] [ 2 ] These chemicals are also called cholinergic drugs because acetylcholine (ACh) is the neurotransmitter used by the PSNS.
There are two different kinds of acetylcholine receptors: nicotinic and muscarinic. Nicotinic receptors are ligand gated ion channels for fast transmission. All acetylcholine receptors in the neuromuscular junction are nicotinic. Muscarinic receptors are G protein-coupled receptors that use a second messenger. These receptors are slow and ...
These receptors were named after muscarine, to differentiate them from the other acetylcholine receptors (nicotinic receptors), which are comparatively unresponsive to muscarine. There are five different types of muscarinic receptors: M 1, M 2, M 3, M 4 and M 5. Most tissues express a mixture of subtypes.
Homopentameric receptors with five acetylcholine binding sites contain two a-subunits (a2-a4 or a6) and two non-a-subunits (B2 or B4). Alpha5 subunits tend to be the fifth that does not directly bind to acetylcholine and act as auxiliary subunits. Rather, they may be important for receptor targeting and localization on the cell membrane. [4]