Methacholine (chloride)

Methacholine (Acetyl-β-methylcholine) choride is a potent muscarinic-3 (M3) agonist. Methacholine choride acts directly on acetylcholine receptors on smooth muscle causing bronchoconstriction and airway narrowing. Methacholine choride shows a high sensitivity to identify bronchial hyperresponsiveness (BHR) . Methacholine choride can be used to measure airway hyperresponsiveness (AHR) as a diagnostic aid in the assessment of individuals with asthma-like symptoms and normal resting expiratory flow rates[1][2][3][4].

Product Specifications

CAS Number

[62-51-1]

Product Name Alternative

Acetyl-β-methylcholine chloride

UNSPSC

12352211

Hazard Statement

H302, H315, H319, H335

Target

MAChR

Type

Reference compound

Related Pathways

GPCR/G Protein; Neuronal Signaling

Field of Research

Others

Assay Protocol

https://www.medchemexpress.com/Methacholine-chloride.html

Purity

98.0

Solubility

DMSO : 100 mg/mL (ultrasonic) |H2O : 100 mg/mL (ultrasonic)

Smiles

CC(OC(C)=O)C[N+](C)(C)C.[Cl-]

Molecular Formula

C8H18ClNO2

Molecular Weight

195.69

Precautions

H302, H315, H319, H335

References & Citations

[1]Cohen J, et al. Relationship between airway responsiveness to neurokinin A and methacholine in asthma. Pulm Pharmacol Ther. 2005;18 (3) :171-176.|[2]Anderson SD, et al. Comparison of mannitol and methacholine to predict exercise-induced bronchoconstriction and a clinical diagnosis of asthma. Respir Res. 2009;10 (1) :4. Published 2009 Jan 23.|[3]Cockcroft DW. Methacholine challenge methods. Chest. 2008;134 (4) :678-680.|[4]Kabara S, et al. Differential effects of thiopental on methacholine- and serotonin-induced bronchoconstriction in dogs. Br J Anaesth. 2003 Sep;91 (3) :379-84.|[5]Folkerts G, et al. Bradykinin causes inhibition of methacholine-induced bronchoconstriction in vivo in mice. Naunyn Schmiedebergs Arch Pharmacol. 2001 Jul;364 (1) :53-8. |[6]Vitorasso RL, et al. Methacholine dose response curve and acceptability criteria of respiratory mechanics modeling. Exp Lung Res. 2020 Feb-Mar;46 (1-2) :23-31.

Shipping Conditions

Room Temperature

Storage Conditions

4°C (Powder, stored under nitrogen, away from moisture)

Scientific Category

Reference compound1

Clinical Information

Launched

Isoform

MAChR3

Citation 01

Aging (Albany NY) . 2021 Sep 13;13 (17) :21729-21742.|Cell Death Dis. 2025 Oct 7;16 (1) :716.|Immunobiology. 2025 Jul 16;230 (4) :153103.|J Ethnopharmacol. 2025 Oct 22:356:120782.|Naunyn Schmiedebergs Arch Pharmacol. 2025 Nov 12.|Mol Immunol. 2023 Oct:162:74-83.