Serotonin7 Receptors (5-HT7Rs)and their Ligands

Serotonin (5-HT)is involved in various physiological and pathological processes by interaction with 14 distinct receptor subtypes,grouped in seven classes of receptors (5-HT 1-7 )on the basis of amino acid sequence,pharmacology,and signal transduction pathways.The 5-HT 7 R is a G-protein coupled receptor with seven transmembrane domains.It was found by the application of molecular cloning and has been identified in rat,mouse,human,pig,and guinea pig.Although the biological functions of the 5-HT 7 Rs are poorly understood,preliminary evidence suggests that it may be involved in depression,control of circadian rhythms,and relaxation of vascular smooth muscles.For these reasons,the 5-HT 7 R has become a target for the development of novel drugs.This review will give a brief introduction of the pharmacology of 5-HT 7 R (molecular structure,distribution of 5- HT 7 R mRNA,localization of the 5-HT 7 R protein,functional correlates,and therapeutic potential)and a detailed survey of the 5-HT 7 R ligands,which have appeared in the literature in both papers and patents.Structure- activity relationships (SAR)of these ligands will also be described.