Imetit dihydrobromide is a high affinity and effective agonist of histamine H3 and H4 receptors (Ki: 0.3 and 2.7 nM). Imetit mimics the histamine effect in triggering a shape change in eosinophils (EC50: 25 nM).
Iodophenpropit dihydrobromide is an effective and selective antagonist of the histamine H3 receptor. The binding of [125I]Iodophenpropit is readily reversible, selective, and of high affinity (KD: 0.32 nM).