Medical College of Wisconsin
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Triphasic effects of short chain n-alcohols on synaptic membrane transport of choline and of gamma-aminobutyric acid. Biochim Biophys Acta 1989 Aug 21;984(1):97-103



Pubmed ID




Scopus ID

2-s2.0-0024374198 (requires institutional sign-in at Scopus site)   3 Citations


n-Alcohols, when added in increasing concentrations, had an unusual triphasic effect on the uptake of choline and of gamma-aminobutyric acid by isolated synaptosomes. There was slight inhibition of these uptakes at low n-alcohol concentrations, followed by a sharp peak of uptake enhancement, and then greater inhibition. The n-alcohol concentrations required for these effects were proportional to published n-alcohol membrane/buffer partition coefficients, with the peaks of uptake enhancement occurring at 60 mM n-propanol, 20 mM n-butanol and 7.5 mM n-pentanol. Synaptosomal membrane potential, as estimated from synaptosomal accumulation of the permeant cation [3H]tetraphenylphosphonium, was not affected by n-alcohols in the concentrations used in this study, suggesting that neither the inhibitory or enhancing effects of these n-alcohols were attributable to changes in trans-synaptosomal membrane ion gradients. The inhibiting and enhancing effects of n-alcohols could be reproduced in determinations of gamma-aminobutyric acid uptake by isolated synaptic plasma membranes, suggesting that the observed effects are due to a direct action of the n-alcohols on the synaptosomal plasma membrane. These effects may be attributable to a change in membrane binding of these alcohols from the membrane core to the membrane surface as alcohol concentration is increased.

Author List

Mrak RE, North PE


Paula E. North MD, PhD Professor in the Pathology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Biological Transport
Cell Membrane
Dose-Response Relationship, Drug
In Vitro Techniques
Membrane Potentials
Rats, Inbred Strains
gamma-Aminobutyric Acid