| 説明 |
Cebranopadol (GRT6005) is an analgesic NOP and opioid receptor agonist with Kis of 0.9 nM, 0.7 nM, 2.6 nM, 18 nM for human NOP, μ-opioid (MOP), κ-opioid (KOP) and δ-opioid (DOP) receptor, respectively. |
| ターゲット＆IC50 |
μ opioid receptor:1.2 nM (EC50, cell free), NOP:13 nM (EC50, cell free), δ opioid receptor:110 nM (EC50, cell free), κ opioid receptor:17 nM (EC50, cell free)
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| In vitro |
Cebranopadol showed full agonistic efficacy at the human MOP and DOP receptors, almost full efficacy at the human NOP receptor, and partial efficacy at the human KOP receptor. In a functional [35S]GTPgS binding assay with membranes expressing the human 5-HT5A receptor, cebranopadol did not show agonistic or signirficant antagonistic effects at concentrations up to 10.0 μM [1].
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| In vivo |
Cebranopadol exhibits highly potent and efficacious antinociceptive and antihypersensitive effects in several rat models of acute and chronic pain with ED50 values of 0.5-5.6 μg/kg after intravenous and 25.1 μg/kg after oral administration. Cebranopadol's duration of action is long (up to 7 hours after intravenous 12 μg/kg; >9 hours after oral 55 μg/kg in the rat tail-flick test) [1]. In streptozotocin (STZ)-treated rats, cebranopadol (i.pl.) reduced mechanical hypersensitivity in the ipsilateral paw but had no effect at the contralateral paw. In CCI rats, cebranopadol (i.pl.) showed antiallodynic activity at the ipsilateral paw. After administration to the contralateral paw, cebranopadol also showed ipsilateral antiallodynic activity, but with reduced potency and delayed onset. In diabetic mice, cebranopadol i.th. and i.c.v. decreased heat hyperalgesia with full efficacy and similar potency for both routes [2]. In NOP(-/-) mice morphine treatment produced the same signs of withdrawal as in NOP(+/+) animals, while cebranopadol treatment elicited a stronger withdrawal syndrome in NOP(-/-) than of NOP(+/+) mice [3].
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| キナーゼ試験 |
Rat MOP, KOP, and NOP receptor binding assays were run using membrane suspensions from rat brain without the cerebellum for MOP receptors; without the pons, medulla oblongata, and cerebellum for NOP receptors; and without the pons, medulla oblongata, cerebellum, and cortex for KOP receptors and the following tritium-labeled radioligands: [3H]DAMGO in the MOP receptor assay, [3H]nociceptin in the NOP receptor assay, and [3H]Ci-977 in the KOP receptor assay. The assay buffer used for the binding studies was 50 mM Tris-HCl (pH 7.4) supplemented with 0.05% sodium azide. The final assay volume of 250 μl/well included 2 nM [3H]DAMGO, 1 nM [3H]nociceptin, or 1 nM [3H]Ci-977 as a ligand in the MOP, NOP, or KOP receptor assays, respectively, and cebranopadol in dilution series. Cebranopadol was diluted with 25% DMSO in water to yield a final 0.5% DMSO concentration, which also served as a respective vehicle control. The assays were started by the addition of the membrane suspensions and, after short mixing, the assays were run for 90 minutes at room temperature. All incubations were run in triplicate and terminated by rapid filtration under mild vacuum and two washes of 5 ml of buffer using FP-100 Whatman GF/B filter mats. The radioactivity of the samples was counted after a stabilization and extraction period of at least 15 hours by use of the scintillation fluid Ready Protein; the complete competition curves for cebranopadol were recorded [1]. |
| 動物実験 |
The pharmacokinetic properties of cebranopadol in rats were investigated after a single intravenous dose of 160 μg/kg cebranopadol. The intravenous dose was administered as a bolus in a volume of 2 ml/kg with a catheter in the vena femoralis. Blood samples (200 μl/sample) were withdrawn via an implanted arterial catheter (arteria carotis) by an automated blood sampling system at the following sampling times: 0 (predose), 5, 15, 30, 60, 180, 360, 720, and 1440 minutes after administration. Blood samples were centrifuged, and plasma was separated. Plasma concentrations of cebranopadol were determined using a validated liquid chromatography-tandem mass spectrometry method. The lower limit of quantification for cebranopadol in this method was 0.05 ng/ml using a sample volume of 50 μl of plasma [1]. |
参考文献
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