Convergent cross-species pro-cognitive effects of RGH-235, a new potent and selective histamine H3 receptor antagonist/inverse agonist

Némethy, Zsolt and Kiss, Béla and Lethbridge, Natasha and Chazot, Paul and Hajnik, Tünde and Tóth, Attila István and Détári, László and Oláh, Vilmos and Hernádi, István and Vizi, E. Szilveszter and Román, Viktor and Lendvai, Balázs and Lévay, György István (2022) Convergent cross-species pro-cognitive effects of RGH-235, a new potent and selective histamine H3 receptor antagonist/inverse agonist. EUROPEAN JOURNAL OF PHARMACOLOGY, 916. ISSN 0014-2999

Text Convergentcross-speciespro-cognitiveeffects....pdf Restricted to Registered users only Download (3MB) | Request a copy

Abstract

The histamine H3 receptor is a favourable target for the treatment of cognitive deficits. Here we report the in vitro and in vivo profile of RGH-235, a new potent, selective, and orally active H3 receptor antagonist/inverse agonist developed by Gedeon Richter Plc. Radioligand binding and functional assays were used for in vitro profiling. Procognitive efficacy was investigated in rodent cognitive tests, in models of attention deficit hyperactive dis- order (ADHD) and in cognitive tests of high translational value (rat touch screen visual discrimination test, primate fixed-foreperiod visual reaction time task). Results were supported by pharmacokinetic studies, neurotransmitter release, sleep EEG and dipsogenia. RGH-235 displayed high affinity to H3 receptors (Ki = 3.0–9.2 nM, depending on species), without affinity to H1, H2 or H4 receptors and >100 other targets. RGH-235 was an inverse agonist ([35S] GTPγS binding) and antagonist (pERK1/2 ELISA), showing favourable kinetics, inhibition of the imetit-induced dipsogenia and moderate effects on sleep-wake EEG. RGH-235 stimulated neurotransmitter release both in vitro and in vivo. RGH-235 was active in spontaneously hypertensive rats (SHR), generally considered as a model of ADHD, and revealed a robust pro-cognitive profile both in rodent and primate tests (in 0.3–1 mg/kg) and in models of high translational value (e.g. in a rodent touch screen test and in non- human primates). The multiple and convergent procognitive effects of RGH-235 support the view that benefi- cial cognitive effects can be linked to antagonism/inverse agonism of H3 receptors.

Actions (login required)

Edit Item