Related Experiment Video
Updated: Aug 14, 2026

Fluorescence-based Monitoring of PAD4 Activity via a Pro-fluorescence Substrate Analog
Published on: November 5, 2014
Flavoxate, a potent phosphodiesterase inhibitor
Flavoxate and its metabolite MFCA are potent phosphodiesterase inhibitors, significantly more effective than theophylline. This enzymatic activity likely explains flavoxate's smooth muscle relaxing effects.
Area of Science:
- Pharmacology
- Biochemistry
Background:
- Cyclic adenosine monophosphate (c-AMP) phosphodiesterase (PDE) enzymes regulate intracellular signaling.
- Smooth muscle relaxation is a critical physiological process influenced by PDE activity.
Purpose of the Study:
- To investigate the c-AMP phosphodiesterase inhibiting properties of flavoxate and its metabolite, 3-methylflavone-8-carboxylic acid (MFCA).
- To compare the potency of flavoxate and MFCA as PDE inhibitors against theophylline.
- To explore the potential enzymatic mechanism underlying flavoxate's smooth muscle relaxing activity.
Main Methods:
- In vitro assay of c-AMP phosphodiesterase inhibition.
- Comparative analysis of inhibitory potency.
Main Results:
- Flavoxate and MFCA were identified as competitive phosphodiesterase inhibitors.
- MFCA was found to be 5 times more potent than theophylline.
- Flavoxate demonstrated 21 times greater potency than theophylline as a phosphodiesterase inhibitor.
Conclusions:
- Flavoxate and its metabolite MFCA exhibit significant in vitro phosphodiesterase inhibitory activity.
- The potent inhibition of phosphodiesterase by flavoxate suggests a primary mechanism for its smooth muscle relaxant effects.
More Related Videos
09:59Functional Reconstitution and Channel Activity Measurements of Purified Wildtype and Mutant CFTR Protein
Published on: March 9, 2015
06:14Optimized LC-MS/MS Method for the High-throughput Analysis of Clinical Samples of Ivacaftor, Its Major Metabolites, and Lumacaftor in Biological Fluids of Cystic Fibrosis Patients
Published on: October 15, 2017
Related Concept Videos
Indirect-Acting Cholinergic Agonists: Mechanism of Action
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex, leading to...
Cognitive Enhancers: Cholinesterase Inhibitors and NMDA Receptor Antagonists
Antiepileptic Drugs: Potassium Channel Activators
Ezogabine has gained approval as an adjunctive treatment...
Acid Suppressive Drugs for Peptic Ulcer Disease: Proton Pump Inhibitors
Gastric acid, a potent cocktail of hydrogen and chloride ions, is produced in specialized parietal cells within the...
Drugs Affecting GI Tract Motility: Dopamine Receptor Antagonists
Antiprotozoal Agents