Abstract

The in vitro pharmacological properties of N-(1-Acetyl-2,3-dihydro-1H-indol-6-yl)-3-(3-cyano-phenyl)-N-[1-(2-cyclopentyl-ethyl)-piperidin-4yl]-acrylamide (JNJ-5207787), a novel neuropeptide Y Y₂ receptor (Y₂) antagonist, were evaluated. JNJ-5207787 inhibited the binding of peptide YY (PYY) to human Y₂ receptor in KAN-Ts cells (pIC₅₀ = 7.00 ± 0.10) and to rat Y₂ receptors in rat hippocampus (pIC₅₀ = 7.10 ± 0.20). The compound was >100-fold selective versus human Y₁,Y₄, and Y₅ receptors as evaluated by radioligand binding. In vitro receptor autoradiography data in rat brain tissue sections confirmed the selectivity of JNJ-5207787. [¹²⁵I]PYY binding sites sensitive to JNJ-5207787 were found in rat brain regions known to express Y₂ receptor (septum, hypothalamus, hippocampus, substantia nigra, and cerebellum), whereas insensitive binding sites were observed in regions known to express Y₁ receptor (cortex and thalamus). JNJ-5207787 was demonstrated to be an antagonist via inhibition of PYY-stimulated guanosine 5′-O-(3-[³⁵S]thio)triphosphate binding ([³⁵S]GTPγS) in KAN-Ts cells (pIC₅₀ corrected = 7.20 ± 0.12). This was confirmed auto-radiographically in rat brain sections where PYY-stimulated guanosine 5′-O-(3-[³⁵S]thio)triphosphate binding was inhibited by JNJ-5207787 (10 μM) in hypothalamus, hippocampus, and substantia nigra. After intraperitoneal administration in rats (30 mg/kg), JNJ-5207787 penetrated into the brain (C_max = 1351 ± 153 ng/ml at 30 min) and occupied Y₂ receptor binding sites as revealed by ex vivo receptor autoradiography. Hence, JNJ-5207787 is a potent and selective pharmacological tool available to establish the potential role of central and peripheral Y₂ receptors in vivo.