Galanin receptor ligands.

The three galanin receptor subtypes (GalR1-3) belong to the G protein-coupled receptor superfamily. The widespread distribution of galanin and its receptors in the CNS and PNS and the numerous physiological and pharmacological effects of galanin (for review, cf. Vrontakis, 2002) render the three galanin receptors attractive drug targets. The industrial efforts, however, have not yet resulted in a wealth of receptor subtype specific agonists or antagonists with high affinity and selectivity. The present paper summarizes the properties of the galanin ligands used at the end of 2004 in the ca. 2000 publications and complements their pharmacological characterization with new data.