@article{APS8844,
author = {Chong-Bin Zhu and Xiu-Lin Zhang and Shao-Fen Xu and Xiao-Ding Cao and Gen-Cheng Wu and Mo-Yi Li and Da-Fu Cui and Zheng-Wu Qi},
title = {Antagonistic effect of orphanin FQ on opioid analgesia in rat},
journal = {Acta Pharmacologica Sinica},
volume = {19},
number = {1},
year = {2016},
keywords = {},
abstract = {AIM: To study the effect of orphanin FQ (OFQ), a newly discovered heptadecapeptide, on nociception and opioid analgesia.
METHODS: The intracerebroventricular (i.c.v.) and intrathecal (i.t.h.) injections were used to give the drugs. The tail-flick model of rats were used to test the pain threshold.
RESULTS: OFQ (i.c.v. or i.t.h.) 0.1 microgram had no effect on nociception but 0.5-10 micrograms induces hyper-reaction of rat to noxious electric stimulus; the decapeptide (OFQ1-10 i.c.v.), a fragment of the OFQ, did not affect the pain reaction of rats. Fentanyl (1 microgram, i.c.v. or i.t.h.), a selective mu-receptor agonist, DSLET (5 micrograms, i.c.v. or i.t.h.), a selective delta-receptor agonist, or U50488H (1 microgram, i.t.h.), a kappa-receptor agonist, induced an increase in pain threshold, when OFQ (0.1 or 1 microgram) was added together with one of them (except for the ith injection of DSLET), the increase of pain threshold was reduced obviously.
CONCLUSION: OFQ induces hyperalgesia and antagonizes opioid analgesia mediated by mu- and delta-receptors in the brain and by mu- and kappa- but not delta-receptors in the spinal cord of rats.},
issn = {1745-7254}, url = {http://www.chinaphar.com/article/view/8844}
}