JTC-801

Kinase experiment:

A suspension of membranes from human μ-opioid receptor-expressing CHO-K1 cells in 50 mM Tris-HCl buffer (pH 7.4) containing 5 mM MgCl2 and 10% sucrose is incubated at room temperature for 2.5 h with 0.33 nM 3H-labeled diprenorphine and various concentrations of JTC-801. The membranes are collected by filtration using Whatman 934-AH, and radioactivity is counted with a TopCount A9912V scintillation counter. Nonspecific binding (6.4%) is determined with 10 μM naloxone. Specific binding is calculated by subtracting nonspecific binding from the total binding. Data are the mean±SE (n=3).

Animal experiment:

The antagonistic effect of naloxone, a non-specific opioid antagonist, on the anti-nociceptive effect of JTC-801 and morphine is examined by formalin stimulation test. Limb licking response is induced by subcutaneous injection of 50 μL of 5% formalin to the left hind limb of each rat. The first 5 min (from immediately after the injection of formalin) and the subsequent 15 min (15-30 min post-injection) are designated as the first and second phases, respectively. The limb licking time during each of the phases is measured and used as an indicator of pain. Fifteen min before the injection of formalin, naloxone (10 mg/kg, dissolved in physiological saline) is given subcutaneously. Five min before the injection of formalin, JTC-801 and morphine are dissolved in 5% sorbitol and given into the tail vein at doses of 0.03 and 1.0 mg/kg, respectively. JTC-801 (3.0 mg/kg) and morphine (30 mg/kg) are administered orally 60 min before the formalin injection.

References:

[1]. Yamada H, et al. Pharmacological profiles of a novel opioid receptor-like1 (ORL(1)) receptor antagonist, JTC-801. Br J Pharmacol, 2002, 135(2), 323-332.
[2]. Koyama T, et al. Nociceptin receptor antagonist JTC-801 inhibits nitrous oxide-induced analgesia in mice. J Anesth. 2009;23(2):301-3.
[3]. Shinkai H, et al. 4-Aminoquinolines: novel nociceptin antagonists with analgesic activity. J Med Chem, 2000, 43(24), 4667-4677.
[4]. Zhang Y, et al. Nociceptin/orphanin FQ peptide receptor antagonist JTC-801 reverses pain and anxiety symptoms in a rat model of post-traumatic stress disorder. Br J Pharmacol. 2015 Jan;172(2):571-82.