Pergolide binds tightly to dopamine D-2 short receptors and induces receptor sequestration

Pergolide is an ergotamine derivative with potent D-1 and D-2 receptor activity. In this study we showed that pergolide binds tightly to dopamine D-2 short receptors, as indicated by the long period of occupancy of the receptors after washing. Furthermore, pergolide induces receptor internalization to a larger extent than dopamine, seeing that no recycling of the receptors to the plasma membrane was observed for either agonist. The dissociation of pergolide from dopamine receptors occurs during the endocytotic process, leaving the receptors accessible to [H-3]methylspiperone. Pergolide is a lipophilic compound that can reach and compete with [H-3]methylspiperone for binding to sequestered receptors. If internalized receptors are still a target for drug action, pergolide could be a suitable compound of therapeutic interest in cases where receptor sequestration could prevent dopamine efficacy, as in levodopa therapy.