Effects of chronic diazepam and medazepam treatment on the level of biogenic monoamines in different rat brain areas.

Studies were made of the effect of 19-day administration of diazepam (1 mg.kg-1, i.p.) and medazepam (5 mg.kg-1, i.p.) on the level of biogenic monoamines in different rat brain areas: cerebral cortex, striatum, hippocampus, and hypothalamus. The noradrenaline (NA), dopamine (DA) and serotonin (5-HT) levels were determined. After chronic treatment with diazepam no alterations in the NA content in the cortex, striatum and hypothalamus were found. Medazepam increased the NA level in the cortex, striatum, and hippocampus without changing it in the hypothalamus. Repeated administration of diazepam or medazepam led to an increase in the DA level in the striatum. Both benzodiazepines provoked a significant increase in the hippocampal 5-HT level, which could be attributed to the antianxiety effect of these drugs.