Related Experiment Video
Updated: Jun 21, 2026

Cerebral Ischemic Coma Model Induced by Modified Four-Vessel Occlusion
Published on: July 5, 2024
4-chloro-3-hydroxyanthranilate inhibits brain 3-hydroxyanthranate oxidase
M P Heyes1, B Hutto, S P Markey
1Laboratory of Neurophysiology, Building 10, Room 3D40 National Institute of Mental Health, Bethesda, MD 20892 USA.
4-chloro-3-hydroxyanthranilic acid inhibits 3-hydroxyanthranilic acid oxidase in the brain. This finding is significant because quinolinic acid, a neurotoxin, is synthesized by this enzyme, potentially impacting neurological health.
Area of Science:
- Neuroscience
- Biochemistry
Background:
- Quinolinic acid (QUIN) is a neurotoxin and an N-methyl-D-aspartate receptor agonist found in the brain.
- QUIN is synthesized from 3-hydroxyanthranilic acid (3-HAA) via 3-hydroxyanthranilic acid oxidase (3-HAA/OX).
- 4-chloro-3-hydroxyanthranilic acid (CL-HAA) is known to inhibit 3-HAA/OX in the liver.
Purpose of the Study:
- To investigate whether CL-HAA inhibits 3-HAA/OX in the brain.
- To determine the effect of CL-HAA on QUIN concentrations in the brain.
Main Methods:
- Rats received intracisternal injections of 3-HAA.
- CL-HAA was co-administered with 3-HAA in some rats.
- Brain QUIN concentrations were quantified using gas chromatography/mass spectrometry.
Main Results:
- Intracisternal injection of 3-HAA increased QUIN concentrations in the brain.
- Co-administration of CL-HAA attenuated the increase in brain QUIN concentrations.
- These results indicate that CL-HAA inhibits 3-HAA/OX in the brain.
Conclusions:
- CL-HAA acts as an inhibitor of 3-HAA/OX in the brain.
- Inhibition of 3-HAA/OX by CL-HAA may influence neurotoxic pathways involving QUIN.
Related Concept Videos
Drugs Affecting Neurotransmitter Synthesis
Indirect-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
Reversible inhibitors display short to medium durations of action. Short-acting agents include simple alcohols with...
Anticholinesterase Agents: Poisoning and Treatment
Irreversible agents form a strong bond with the cholinesterase enzyme, making it inactive. The breakdown of the phosphorylated enzyme is slower than the...

