The interrelationship between hormones, psychotropic drugs and the opiate receptor--a pilot study

Earlier reports had shown pronounced effects of clomipramine on plasma pituitary and gonadal hormone levels. In a continuation of these studies no change could be seen in rat plasma corticosterone levels following long-term, toxic administration of the drug despite a marked adrenal hyperplasia. It had been suggested that the action of clomipramine might be potentiated through the opiate receptor. Initial experiments using a rat model system have shown that morphine increased plasma prolactin and reduced plasma luteinizing hormone levels in vivo and that these effects could be overcome by naloxone. No direct effect of enkephalins was observed on rat pituitary organ cultures. The results are discussed in the light of recent findings of the relationship between properties of the opiate receptor and the observed side effects of tricyclic antidepressant therapy.