Alcohol-membrane interaction in the brain: norepinephrine release.

The nerve endings of mouse brain were loaded with 3H-norepinephrine (3H-NE) by intraventricular injection of 3H-NE. After dissection of brain, the synaptosomal particles were isolated and used for NE-release studies. The NE release process was stimulated by K+ and Ca++ but was antagonized by Na+. Acetylcholine at low concentration also decreased the release of 3H-NE. Ethanol at low concentrations (0.1-0.5%) decreased the amount of synaptosomal NE release whereas at higher ethanol concentrations (1-4%) the NE release was increased. This biphasic response of NE release in the presence of ethanol could be the effect of ethanol on related active cation transport systems such as Ca++-transport.