δ-Opioid receptor binding sites in rodent spinal cord
Article first published online: 19 JUL 2012
1990 British Pharmacological Society
British Journal of Pharmacology
Volume 100, Issue 2, pages 319–323, June 1990
How to Cite
Traynor, J.R., Hunter, J.C., Rodriguez, R.E., Hill, R.G. and Hughes, J. (1990), δ-Opioid receptor binding sites in rodent spinal cord. British Journal of Pharmacology, 100: 319–323. doi: 10.1111/j.1476-5381.1990.tb15802.x
- Issue published online: 19 JUL 2012
- Article first published online: 19 JUL 2012
- Received July 31, 1989; Revised January 15, 1990; Accepted January 29, 1990
- 1The δ-opioid receptor agonist [d-Pen2,d-Pen5]enkephalin showed an antinociceptive effect in the mouse tail-flick test, following intrathecal administration. This action was reversed by naloxone and by the selective δ-opioid receptor antagonist ICI 174864.
- 2High affinity, saturable binding of [3H]-[d-Pen2,d-Pen5]enkephalin has been demonstrated in spinal cord homogenates from guinea-pig, hamster, rat and both adult and young (18–20 g) mice. The binding was shown by autoradiography to be concentrated in the superficial laminae of the dorsal horn.
- 3Competition studies confirmed that the binding of [3H]-[d-Pen2,d-Pen5]enkephalin was to the δ-opioid site. However, anomalies were seen with displacement assays using μ-ligands, which may suggest some common high affinity site for δ- and μ-opioid receptor agonists in the spinal cord.
- 4The results add further evidence for a role of the δ-opioid receptor in spinally-mediated antinociception.