How selective is GR 43175? Interactions with functional 5-HT1A, 5-HT1B, 5-HT1C and 5-HT1D receptors

Abstract

GR 43175 (3-[2-dimethylamino]ethyl-N-methyl-1H-indole-5 methane sulphonamide) is a novel 5-HT1-like receptor-selective agonist which was reported to be active in the treatment of migraine attacks. The effects of the compound were investigated in radioligand binding studies and in functional models for 5-HT1A, 5-HT1B, and 5-HT1D receptors (inhibition of forskolin-stimulated adenylate cyclase activity in calf hippocampus, rat and calf substantia nigra, respectively) and 5-HT1C receptors (stimulation of inositol phosphate production in pig choroid plexus). GR 43175 displayed the following order of affinity for 5-HT recognition sites (pKD values, -log mol/l, in parentheses): 5-HT1D (7.54) > 5-HT..