Variability of chronic antidepressant treatments on beta-adrenergic receptor sites.

It has been proposed that down-regulation of beta-adrenergic receptors may be related to the therapeutic action of antidepressants. To further characterize the role of beta-adrenergic receptor regulation in the actions of antidepressants, the effects of chronic treatment with desipramine, zimelidine and bupropion on beta-adrenergic receptors in rat brain membrane preparations were studied. Chronic treatment with desipramine, but not zimelidine and bupropion decreased significantly the density of beta-adrenergic receptors. These data suggest that clinically effective antidepressants may vary considerably in their ability to down-regulate beta-adrenergic receptors after chronic treatment.