Combined effects of desipramine and stress on monoamine turnover in rat brain

Because depression is often associated with stress, it has been hypothesized that antidepressants may influence stress-related adaptive responses in the brain. This issue was addressed in the present study designed to compare the effects of desipramine (DMI) administration and stress on monoamine metabolism in rat brain. Rats were housed in crowded conditions for 3 to 14 days and injected with DMI or saline at various times during treatment. Animals were decapitated, after which norepinephrine (NE), serotonin (5-HT), and their metabolites were measured in various brain regions by high-performance liquid chromatography using electrochemical detection. The results indicate that DMI administration increased 5-HT turnover in all regions and NE turnover in the hypothalamus when administered for 14 days to animals housed under crowded conditions. In conclusion, DMI had a different effect on rat brain monoamine turnover under the crowded stress conditions when compared with control animals. In addition, the turnover of NE and 5-HT in some regions of the brain was augmented when DMI and stress were combined.