The first radiolabeled histamine H3 receptor antagonist, [125I]iodophenpropit: Saturable and reversible binding to rat cortex membranes

Evaluation of Histamine H1-, H2-, and H3-Receptor Ligands at the Human Histamine H4 Receptor: Identification of 4-Methylhistamine as the First Potent and Selective H4 Receptor Agonist

“…As observed for their action at the hH 3 R, both compounds act as partial agonist at the hH 4 R ( (Oda et al, 2000;Liu et al, 2001a;Morse et al, 2001;Nguyen et al, 2001;Zhu et al, 2001;Thurmond et al, 2004). Previously, we described [ 125 I]iodophenproprit as a suitable high affinity H 3 R radioligand (Jansen et al, 1992). Considering, the relatively high affinity of iodophenpropit at the hH 4 R and its high sensitivity, we investigated the potential of this radioligand to label the H 4 R. Due to the hH 4 R affinity of (Fig.…”

International Union of Basic and Clinical Pharmacology. XCVIII. Histamine Receptors

“…The first compound to be developed was [ 125 I]iodophenpropit, which has been used to successfully label H 3 receptors in rat brain membranes (Jansen et al, 1992). Inhibition curves for thioperamide and iodophenpropit were consistent with interaction with a single binding site, but H 3 receptor agonists were able to discriminate high [4 nM for (R)-a-methylhistamine]-and low [0.2 mM for (R)-a-methylhistamine]-affinity binding sites (Jansen et al, 1992 (Stark et al, 1996) is the most potent and selective ligand available at the present time, with a K D of 65 pM (Ligneau et al, 1994).…”

“…The first compound to be developed was [ 125 I]iodophenpropit, which has been used to successfully label H 3 receptors in rat brain membranes (Jansen et al, 1992). Inhibition curves for thioperamide and iodophenpropit were consistent with interaction with a single binding site, but H 3 receptor agonists were able to discriminate high [4 nM for (R)-a-methylhistamine]-and low [0.2 mM for (R)-a-methylhistamine]-affinity binding sites (Jansen et al, 1992 (Stark et al, 1996) is the most potent and selective ligand available at the present time, with a K D of 65 pM (Ligneau et al, 1994). In rat striatum, in the presence of guanine nucleotides such as guanosine (3-thiotriphosphate) (GTPgS), 40% of the binding sites exhibited a 40-fold lower affinity for H 3 receptor agonists, providing further evidence for a potential linkage of the H 3 receptor to G proteins (Ligneau et al, 1994 (Amon et al, 2006(Amon et al, , 2007.…”

Histamine H3 activation depresses cardiac function in experimental sepsis

“…The H3 receptor is thought to belong to the superfamily of Jansen et al, 1992;Zweig et al, 1992). The possibility of G-protein involvement is strengthened by the attenuated effects on H3 receptor function, which was caused by the Gprotein toxins, cholera and PTX (Chenfi et al, 1992;Nozaki and Sperelakis, 1989;Endou, et al, 1994).…”