Neurobiology of Alcohol: Introduction | cAMP Pathways | Neurotransmitter Systems and Ethanol | Ethanol Interactions With Ion Channels | Conclusion | Key Points | References | Suggested Reading
Ethanol is a small molecule that readily distributes
into highly perfused tissues such as the brain. Peak levels of ethanol
are attained approximately 30 minutes after ingestion of an alcoholic
drink. A single drink of ethanol produces a biphasic effect with
a rapid stimulatory phase associated with an increase in blood ethanol
concentrations followed by a depressant phase as the blood concentration
diminishes. Although the ethanol from a single drink is readily
metabolized in two steps involving the enzymes alcohol dehydrogenase
and aldehyde dehydrogenase, this process follows zero-order kinetics.
Accordingly, there is a decrease in the percentage of ethanol metabolized
per given unit of time, as the dose of this agent is increased.