ALTERATIONS IN MONOAMINE LEVELS IN DISCRETE REGIONS OF RAT-BRAIN AFTER CHRONIC ADMINISTRATION OF CARBAMAZEPINE

Carbamazepine (25 mg/kg body weight) was administered intraperitoneall y to adult male Wistar rats for 45 days and norepinephrine (NE), dopam ine (DA) and serotonin (5-HT) levels were simultaneously assayed in di screte brain regions by high performance liquid chromatographic (HPLC) method. Experimental rats displayed no behavioral abnormalities. Body and brain weights were not significantly different from control group of rats. After exposure it was observed that norepinephrine levels we re elevated in motor cortex (P<0.01) and cerebellum (P<0.05), while do pamine levels were decreased in these two regions (P<0.001, P<0.05). H owever, dopamine levels were increased in hippocampus (P<0.01). Seroto nin levels were significantly decreased in motor cortex (P<0.001) and hypothalamus (P<0.001) but increased in striatum-accumbens (P<0.001) a nd brainstem (P<0.001). These results suggest that carbamazepine may m ediate its anticonvulsant effect by differential alterations of monoam ine levels in discrete brain regions particularly in motor cortex and cerebellum.