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Updated: Oct 13, 2026

Use of the Operant Orofacial Pain Assessment Device (OPAD) to Measure Changes in Nociceptive Behavior
Published on: June 10, 2013
Agonistic effects of the opioid buprenorphine on the nociceptin/OFQ receptor
P Bloms-Funke1, C Gillen, A J Schuettler
1Grünenthal GmbH, Zieglerstr. 6, D-52078, Aachen, Germany.
Abstract:
The nociceptin/orphanin FQ (N/OFQ) receptor (e.g. the human ortholog ORL1) has been shown to be pharmacologically distinct from classic opioid receptors. Recently, we have identified buprenorphine as a full ORL1 agonist using a reporter gene assay. For further functional analysis, buprenorphine's effects on ORL1 receptors were investigated using a K(+) channel (GIRK1) assay in Xenopus oocytes and GTPgammaS assay in CHO-K1 membrane preparations. In both assays, buprenorphine behaved as a partial agonist compared to nociceptin itself. The N/OFQ agonism of buprenorphine might contribute to actions of buprenorphine in pain models in vivo beside its mu- or kappa-opioid receptor mediated effects.
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