5-HT1D binding sites in various species: similar pharmacological profile in dog, monkey, calf, guinea-pig and human brain membranes

Abstract

Radioligand binding studies were performed in membranes of calf caudate, guinea-pig cortex, dog caudate and whole brain, monkey caudate and whole brain, and human caudate using the novel iodinated radioligand, Serotonin-5-O-Carboxymethyl-Glycyl[125I] Tyrosinamide (abbreviated [125I]GTI for the sake of simplicity), a ligand known to label 5-HT 1B and 5-HT 1D sites. In all membrane preparations tested, [125I]GTI labelled high affinity sites with the following rank order of affinity: 5-carboxamidotryptamine > 5-HT = DHE = ergotamine >- sumatriptan >- metergoline = CGS 12066 >- yohimbine = methysergide >- methiothepin > 8-OHDPAT >_ mianserin >- CP 93129 >- (−)pindolol = ketanserin >_ isamoltane ..