World Library  
Flag as Inappropriate
Email this Article

Muscarinic agonist

Article Id: WHEBN0004250128
Reproduction Date:

Title: Muscarinic agonist  
Author: World Heritage Encyclopedia
Language: English
Subject: Neuromodulation, Nootropics, SIB-1553A, TC-1827, Adafenoxate
Collection: Muscarinic Agonists
Publisher: World Heritage Encyclopedia

Muscarinic agonist

A muscarinic receptor agonist is an agent that activates the activity of the muscarinic acetylcholine receptor. The muscarinic receptor has different subtypes, labelled M1-M5, allowing for further differentiation.


  • Clinical significance 1
    • M1 1.1
    • M3 1.2
  • Muscarinic versus nicotinic activity 2
  • Muscarinic Acetylcholine Receptor Subtypes 3
  • See also 4
  • References 5
  • External links 6

Clinical significance


M1-type muscarinic acetylcholine receptors play a role in cognitive processing. In Alzheimer disease (AD), amyloid formation may decrease the ability of these receptors to transmit signals, leading to decreased cholinergic activity. As these receptors themselves appear relatively unchanged in the disease process, they have become a potential therapeutic target when trying to improve cognitive function in patients with AD.[1][2][3]

A number of muscarinic agonists have been developed and are under investigation to treat AD. These agents show promise as they are neurotrophic, decrease amyloid depositions, and improve damage due to oxidative stress. Tau-phosphorylation is decreased and cholinergic function enhanced. Notably several agents of the AF series of muscarinic agonists have become the focus of such research:. AF102B, AF150(S), AF267B. In animal models that are mimicking the damage of AD, these agents appear promising.

The agent xanomeline has been proposed as a potential treatment for schizophrenia.[4][5]


In the form of pilocarpine, muscarinic receptor agonists have been used medically for a short time.

Muscarinic versus nicotinic activity

Comparison of cholinergic agonists [6]
Substance Receptor specificity Hydrolysis by
Muscarinic Nicotinic
Choline +++ +++ ++ Essential nutrient
Acetylcholine +++ +++ +++ Endogenous ligand
Carbachol ++ +++ - Used in the treatment of glaucoma
Methacholine +++ + ++ Used to diagnose bronchial hyperreactivity,[7] a hallmark of asthma and COPD.
Bethanechol +++ - - Used in bladder and gastrointestinal hypotonia.
Muscarine +++ - - Natural alkaloid found in certain mushrooms. Cause of mushroom poisoning
Nicotine - +++ - Natural alkaloid found in the tobacco plant.
Pilocarpine ++ - - Used in glaucoma.
Oxotremorine ++ - - Used in research to induce symptoms of Parkinson's disease.

Muscarinic Acetylcholine Receptor Subtypes

The targets for Muscarinic agonists include the following receptors:
Receptor/Transporter Protein

See also


  1. ^ Fisher A, Brandeis R, Bar-Ner RH, Kliger-Spatz M, Natan N, Sonego H, Marcovitch I, Pittel Z. AF150(S) and AF267B: M1 muscarinic agonists as innovative therapies for Alzheimer's disease. J Mol Neurosci. 2002 Aug-Oct;19(1-2):145-53. PMID 12212772
  2. ^ Fisher A. M1 muscarinic agonists: Their potential in treatment and as disease-modifying agents in Alzheimer's disease Drug Dev. Res. 50:291-297, 2000. [1]
  3. ^ Fisher A (July 2008). "Cholinergic treatments with emphasis on m1 muscarinic agonists as potential disease-modifying agents for Alzheimer's disease".  
  4. ^ Shekhar A, Potter WZ, Lightfoot J, et al. (July 2008). "Selective Muscarinic Receptor Agonist Xanomeline as a Novel Treatment Approach for Schizophrenia". Am J Psychiatry 165 (8): 1033–9.  
  5. ^ Sellin AK, Shad M, Tamminga C. (November 2008). "Muscarinic agonists for the treatment of cognition in schizophrenia". CNS Spectrums 13 (1): 985–96.  
  6. ^ Unless else specified in boxes, then reference is: Table 10-3 in: Rod Flower; Humphrey P. Rang; Maureen M. Dale; Ritter, James M. (2007). Rang & Dale's pharmacology. Edinburgh: Churchill Livingstone.  
  7. ^ Birnbaum S, Barreiro TJ (June 2007). "Methacholine challenge testing: identifying its diagnostic role, testing, coding, and reimbursement". Chest 131 (6): 1932–5.  

External links

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.