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

Contents 1 Clinical significance 1.1 M1 1.2 M3 2 See also 3 References 4 External links

[edit] Clinical significance

[edit] M1

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 their signals leading to decrease 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]

[edit] M3

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

• M3 agonists
  • Aceclidine, for glaucoma.
  • Arecoline, an alkaloid present in the Betel nut.
  • Pilocarpine is a drug that acts as a muscarinic receptor agonist that is used to treat glaucoma.
  • Cevimeline (AF102B) (Evoxac™) is a muscarinic agonist that is an Food and Drug Administration (FDA)-approved drug and used for the management of dry mouth in Sjögren's syndrome.

[edit] See also

• Muscarine

[edit] References

[edit] External links

• MeSH Muscarinic+Agonists

v • d • e Neuromodulation Types Enzyme: Inducer • Inhibitor Ion Channel: Opener • Blocker Receptor: Agonist • Antagonist • Positive Allosteric Modulator (PAM) • Negative Allosteric Modulator (NAM) Transporter [Reuptake]: Enhancer (RE) • Inhibitor (RI) • Releaser (RA) Miscellaneous: Precursor • Cofactor Classes Enzyme (refer to Enzyme Inhibitors for more details) Ion Channel Calcium Channel Blocker (CCB) • Potassium Channel Blocker (PCB) • Sodium Channel Blocker (SCB) • Potassium Channel Opener (PCO) Receptor & Transporter Adrenergic Adrenergic Receptor Agonist (α, β (1, 2)) • Adrenergic Receptor Antagonist (α (1, 2), β) • Adrenergic Reuptake Inhibitor (ARI) Cholinergic Acetylcholine Receptor Agonist (Muscarinic, Nicotinic) • Acetylcholine Receptor Antagonist (Muscarinic, Nicotinic (Ganglionic, Muscular)) Dopaminergic Dopamine Receptor Agonist • Dopamine Receptor Antagonist • Dopamine Reuptake Inhibitor (DRI) Endocannabinoid Cannabinoid Receptor Agonist • Cannabinoid Receptor Antagonist Histaminergic Histamine Receptor Agonist • Histamine Receptor Antagonist (H1, H2, H3) GABAergic GABA Receptor Agonist • GABA Receptor Antagonist • GABA Reuptake Inhibitor (GRI) Glutamatergic Glutamate Receptor Agonist (AMPA) • Glutamate Receptor Antagonist (NMDA) Opioid Opioid Receptor Agonist • Opioid Receptor Antagonist Serotonergic Serotonin Receptor Agonist (5-HT4) • Serotonin Receptor Antagonist (5-HT3) • Serotonin Reuptake Inhibitor (SRI) • Serotonin Reuptake Enhancer (SRE) Other Adenosine Reuptake Inhibitor (AdoRI) • Angiotensin Receptor Antagonist • Endothelin Receptor Antagonist • NK1 Receptor Antagonist • Vasopressin Receptor Antagonist Miscellaneous Cofactor (see Enzyme Cofactors) • Precursor (see Amino Acids)

v • d • e Parasympathomimetics / cholinergic agonists / acetylcholinesterase inhibitors (N06DA, N07AA) Direct (at receptor) muscarinic: Muscarine  · Oxotremorine  · M1 (Vedaclidine • Xanomeline)  · M3 (Bethanechol, Pilocarpine, Arecoline, Cevimeline, Aceclidine)  · Methacholine nicotinic: Nicotine (low doses) · Lobeline · Varenicline · Epibatidine  · Dimethylphenylpiperazinium M & N: Acetylcholine/Choline alfoscerate · Carbachol Indirect/AIs (in synapse) Reversible very short acting: Edrophonium carbamates/stigmine: Ambenonium · Rivastigmine · Distigmine · tertiary/CNS (Physostigmine) · quaternary/peripheral (Neostigmine, Pyridostigmine) anti-dementia (Galantamine, Donepezil, Tacrine) Irreversible/ organophosphate ophthalmological (Ecothiopate, Isoflurophate, Demecarium) antiparasitic (Malathion, Metrifonate) chemical warfare (see Nerve agent)