Investigation of Orphanin FQ-stimulated [35S]GTPgammaS Binding in the Whole Brain of Mice: Does Orphanin FQ Have Anti-opioid Effect in the Level of Receptor-ligand Interaction and [35S]GTPgammaS Activation?

Lee,  Heeseung; Lee,  Eui Min

doi:2007.53.1.91

Original Article

Korean Journal of Anesthesiology 2007;53(1):91-96.
DOI: https://doi.org/10.4097/kjae.2007.53.1.91

Investigation of Orphanin FQ-stimulated [35S]GTPgammaS Binding in the Whole Brain of Mice: Does Orphanin FQ Have Anti-opioid Effect in the Level of Receptor-ligand Interaction and [35S]GTPgammaS Activation?

Heeseung Lee, Eui Min Lee

Department of Anesthesiology and Pain Medicne, School of Medicine, Ewha Womans University, Seoul, Korea. leehee@ewha.ac.kr

Abstract

BACKGROUND
This study was examined whether or not the orphanin FQ (OFQ)-stimulated [35S]GTPgammaS activity interact with DAMGO in the whole brain of mice.
METHODS
ICR mice (male, n = 20, 20-25 g) were euthanized for the membrane preparations. In the agonist-stimulated [35S]GTPgammaS binding dose-response curves by OFQ, Ro-64-6198 and DAMGO, the EC50 (effective concentration 50, nM) and maximum stimulation (% over basal) were determined in the presence or absence of J-113397 (10 nM), a NOP (nociceptin-opioid peptide) receptor antagonist. OFQ (1micrometer), Ro-64-6198 (10micrometer), DAMGO (10micrometer) and their combination cocktail were used to determine the interaction between the NOP and MOP (micron-opioid peptide) receptor.
RESULTS
The values of EC50 and maximum stimulation of [35S]GTPgammaS binding were as follows: OFQ (9.2 +/- 0.2 nM/17.9 +/- 0.1%), Ro-64-6198 (143.5 +/- 0.5 nM/18.1 +/- 0.4%), and DAMGO (680.6 +/- 0.7 nM/18.1 +/- 0.5%). J-113397 produced a 8.7 and 7.1 fold rightward shifting in the OFQ and Ro-64-6198-stimulated [35S]GTPgammaS binding dose-response curve respectively, but not in the DAMGO. OFQ combined with DAMGO-stimulated [35S]GTPgammaS binding had an additive effect, but not in the OFQ combined with Ro-64-6198.
CONCLUSIONS
OFQ, Ro-64-6198 and DAMGO-stimulated [35S]GTPgammaS binding in the brain of mice has receptor selectivity. The [35S]GTPgammaS stimulation of OFQ and DAMGO had an additive effect rather than an anti-opioid effect on the level of intracellular signal transduction through agonist-stimulated [35S]GTPgammaS bindings.

Key Words: DAMGO; GTPgammaS; J-113397; mice; orphanin FQ; Ro-64-6198