SUMMARY

The rat 5-hydroxytryptamine (5-HT)F (serotonin2F) receptor is a newly cloned member of the 5-HT211 receptor family. The phar-macology of the 5-HT2F receptor was explored using a variety of structurally different compounds in a radioligand binding assay. In addition, the 5-HT2F receptor was shown to stimulate produc-tion of inositol 1,4,5-tnsphosphate in the transformed cells. Based on the affinities of the compounds tested, their known affinities for certain of the other 5-HT receptors, and the fact that activation of the cloned 5-HT2F receptor stimulates inositol 1,4,5-tnsphosphate production, the 5-HT2F receptor was determined to be a novel receptor and a member of the 5-HT211 receptor family. In addition, several agonists and partial agonists were evaluated for contractile activity in the rat stomach fundus, and these activities were correlated with their binding affinities at the 5-HT2F receptor. A highly significant correlation was found, pro