ETHANOL INDUCES AN INCREASE OF HARMAN IN THE BRAIN AND URINE OF RATS

Harman occurs in rat brain, with the highest concentration in the cerebellum and lowest in the striatum. Ethanol 2 g/kg were ineffective with respect to the harman concentration in the brain; 5 g/kg ethanol caused a time-dependent increase in the cerebral cortex and the cerebellum. A toxic dose (8 g/kg) of ethanol elicited no change of harman in the brain 3 h following the application. The rise in harman concentration in the brain did not correlate with the increase of acetaldehyde in the blood after treatment with ethanol. Several mechanisms apparently are involved in the changes of harman levels. In subchronic experiments, rats were treated with ethanol for 5 or 6 days. Harman increased in the brain; the effect seemed more pronounced in the cerebellum than in the cerebral cortex. The concentration tended to increase over time and reached control levels again during withdrawal. The time course of harman excretion into the urine was similar the brain in that it increased continuously during the ethanol treatment period and reached control levels again during withdrawal.