Imipramine: Effect of ovarian steroids on modifications in serotonin receptor binding

Long-term administration of imipramine caused a decrease in serotonin ₂ receptor binding in rat brain cerebral cortex, an effect that was abolished by ovariectomy. In contrast, ovariectomy had no effect on imipramine-induced decreases in hippocampal serotonin or in cerebral cortical and hippocampal β-adrenergic receptor binding. Administration of estradiol or progesterone separately or in combination reestablished the effect of imipramine treatment on cortical serotonin₂ receptors. These results suggest that ovarian steroids may play an important, but subtle, role in the neurochemical and perhaps clinical response to this drug.