Acetylcholine receptors
Acetylcholine receptors (also shortened to cholinoceptors ) are transmembrane receptors in different areas of the nervous system that bind the neurotransmitter acetylcholine (ACh) as a substrate .
There are two types of ACh receptors, the nicotinic acetylcholine receptors (nAChR) and the muscarinic acetylcholine receptors (mAChR).
Nicotinic acetylcholine receptors
Nicotinic acetylcholine receptors are ionotropic , ie they are themselves ion channels (first messenger). Their effect is usually excitatory (arousing). They can be activated by nicotine or indirectly by physostigmine ( acetylcholinesterase inhibitor) by increasing the acetylcholine concentration in the synaptic cleft and are therefore called n-acetylcholine receptors. The antagonist is curare (ACh inhibitor).
A distinction is made between the following subtypes:
- n 1 (motorized end plate)
- n 2 (neuronal, pre- to postganglionic)
Muscarinic acetylcholine receptors
Muscarinic acetylcholine receptors are metabotropic , that is, G-protein coupled. They can be activated by muscarin (alkaloid from the toadstool ; agonist ), which is why they are also known as m-acetylcholine receptors. They are inhibited by atropine and other ACh inhibitors and antagonists .
A distinction is made between the following subtypes:
literature
- Schmidt, Robert F .; Schaible, Hans-Georg (Ed.): Neuro- and sensory physiology. Berlin: Springer, 2006 (5th edition) ISBN 3-540-25700-4
- Kandel, Eric et al. (Ed.): Neurosciences, Spectrum 1995, ISBN 3-86025-391-3
- Stryer, Lubert: Biochemie, Spectrum 1994, ISBN 3-86025-005-1
- Pharmacology and Toxicology , Lüllmann, Mohr, Wehling, Thieme Verlag, 15th edition 2003, ISBN 3-13-368515-5
- Pharmacology and Toxicology , Aktories et al., Urban & Fischer, 9th edition 2005
- Neuroscience Including Sylvius , Purves et al., 3rd edition 2004, Sinauer Verlag, ISBN 0-87893-725-0
- From Neuron To Brain , Nicholls, Martin, Wallace, Fuchs, 4th edition 2001, Sinauer Verlag, ISBN 0-87893-439-1
Web links
- Jennifer McDowall / Interpro: Protein Of The Month: Acetylcholin receptors. (engl.)