Not only dopamine D2 receptors involved in Peony-Glycyrrhiza Decoction, an herbal preparation against antipsychotic-associated hyperprolactinemia

► PGD suppressed prolactin hyperactivity in MMQ cells, but not in GH3 cells. ► PGD enhanced D2 receptor and dopamine transporter expression in PC12 cells. ► Chronic PGD reduced elevated serum PRL in a rat model of hyperPRL.