Cyclo(glycyl-L-leucyl)

Cyclo(glycyl-L-leucyl) (Cyclo(leu-gly)), a neuropeptide, down-regulates dopamine (DA) receptors and attenuates dopaminergic supersensitivity. Cyclo(glycyl-L-leucyl) inhibits the development of Morphine induced pain relief as well as dopamine receptor supersensitivity in rats. Cyclo(glycyl-L-leucyl) has the potential for the prevention of tardive and/or L-DOPA (HY-N0304)-induced dyskinesias.