Ethanol inhibition of adenosine 5′-triphosphate-activated current in freshly isolated adult rat hippocampal CA1 neurons

• Published in: Neuroscience letters 2000-12, Vol.295 (3), p.77-80
• Main Authors: Li, Chaoying, Xiong, Keming, Weight, Forrest F
• Format: Article
• Language: English
• Subjects: Adenosine 5′-triphosphate; Adenosine Triphosphate - metabolism; Adenosine Triphosphate - pharmacology; Alcohol; Alcoholism and acute alcohol poisoning; Animals; Biological and medical sciences; Cells, Cultured - cytology; Cells, Cultured - drug effects; Cells, Cultured - metabolism; Dose-Response Relationship, Drug; Ethanol - pharmacology; Hippocampus; Hippocampus - cytology; Hippocampus - drug effects; Hippocampus - metabolism; Ion channels; Male; Medical sciences; Membrane Potentials - drug effects; Membrane Potentials - physiology; Neurons - cytology; Neurons - drug effects; Neurons - metabolism; P2X receptors; Rats; Rats, Sprague-Dawley; Receptors, Purinergic P2 - drug effects; Receptors, Purinergic P2 - metabolism; Toxicology
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/S0304-3940(00)01586-X

The effect of ethanol on current activated by extracellular adenosine 5′-triphosphate (ATP) was studied in freshly isolated adult rat hippocampal CA1 neurons using whole-cell patch-clamp recording. ATP activated an inward current with an EC 50 value of 18 μM. The inward current was also activated by 2-methylthio ATP (2-MeSATP) and α,β-methylene ATP (α,β-MeATP), inhibited by pyridoxal-phosphate-6-azophenyl-2′,4′-disulfonic acid (PPADS), and potentiated by Zn 2+. Ethanol inhibited current activated by 10 μM ATP with an IC 50 value of 83 mM in a voltage-independent manner. Ethanol, 100 mM, shifted the ATP concentration-response curve to the right, increasing the EC 50 value for ATP from 18 to 33 μM, but did not reduce the maximal response to ATP. The results suggest that ethanol can inhibit the function of P2X receptors in adult rat hippocampal neurons by decreasing the apparent affinity of the binding site for ATP.