Pineal function during ethanol intoxication, dependence, and withdrawal

Pineal melatonin and serotonin content were determined during one to four days of continuous intoxication, and during the alcohol withdrawal syndrome. The nocturnal rise in pineal melatonin was blunted in continuously intoxicated animals, however this was found to be unrelated to duration of treatment. The initial dependent-intoxicated phase of the alcohol withdrawal syndrome produced a reduction of nocturnal pineal melatonin content with a concomitant elevation in pineal serotonin. The overt withdrawal phase of the alcohol withdrawal syndrome had no effect on pineal melatonin or serotonin content. This data suggests that ethanol may perturb pineal melatonin synthesis either directly, or indirectly by altered receptor function. Contrary to our expectations the pineal may not be a useful model to probe the physiology of increased noradrenergic neurotransmission produced by ethanol withdrawal.