Effects of chronic antidepressant and benzodiazepine treatment on corticotropin-releasing-factor receptors in rat brain and pituitary.

We examined the effects of chronic treatment with antidepressants (imipramine or desipramine) or benzodiazepines (diazepam, alprazolam, or adinazolam) on modulation of corticotropin-releasing-factor (CRF) receptors in discrete areas of rat brain and in anterior pituitary. As previously reported, we found that chronic antidepressant treatment downregulated 5-HT2 serotonin and beta-adrenergic receptors in cerebral cortex. Although there was a trend toward increased CRF binding in brain stem, striatum, cerebellum, hypothalamus, and frontal cerebral cortex following antidepressant treatment, the changes were only statistically significant in brain stem in imipramine-treated rats. In addition, no significant changes were seen in CRF binding in other brain regions including parietal/temporal cerebral cortex, olfactory bulb, hippocampus, and anterior pituitary. Following chronic benzodiazepine treatment CRF receptor binding was significantly decreased in the frontal cerebral cortex and hippocampus; although there was a trend for CRF receptors to be decreased in other brain areas and increased in anterior pituitary, the changes were not statistically significant.