Noradrenergic sensitivity of the cerebral cortex after chronic ethanol ingestion and withdrawal

The effects of both chronic ethanol treatment and 3 days of ethanol withdrawal on the cyclic adenosine 3':5'-monophosphate (cAMP) response of cerebral cortical slices to norepinephrine (NE) were studied. ED50 cAMP responses for each group were determined using graded doses of NE. Chronic ethanol fed rats displayed subsensitivity to NE. There was a 4.3-fold shift of the dose-response curve to the right. Rats chronically fed ethanol and then put on 3 days of ethanol withdrawal developed supersensitivity. There was a 2.4-fold shift of the dose-response curve to the left. There was no difference in the maximal cAMP response observed in either the chronic alcohol or the chronic alcohol three day withdrawal experiments. It is possible that the biphasic modifications of effectors by ethanol ingestion and withdrawal from a subsensitive to a supersenitive is the result of one basic phenomenon.