University of Surrey

Test tubes in the lab Research in the ATI Dance Research

The Ontogeny of Delta and Kappa Opioid Receptors in The Rat.

Kelly, Mary D. W. (1996) The Ontogeny of Delta and Kappa Opioid Receptors in The Rat. Doctoral thesis, University of Surrey (United Kingdom)..

[img]
Preview
Text
27621039.pdf
Available under License Creative Commons Attribution Non-commercial Share Alike.

Download (7MB) | Preview

Abstract

Saturation binding studies with the κ1-selective agonists [3H]U-69,593 and [3H]CI-977 have been used to quantify κ1-receptor development in the neonatal rat brain. Full development of κ1-receptors has been demonstrated at post-natal day 1 and characterised as κ1 by competition studies using the selective κ1-agonist U-69,593, the selective μ-agonist DAGO, the selective δ-agonist DPDPE and the opioid antagonist naloxone v. [3H]CI-977. Functional κ1-mediated antinociception against thermal and mechanical noxious stimuli and naloxone reversal has been demonstrated using the κ1-selective agonists PD117,302, U-69,593 and CI-977 in 5 and 10 day-old rat pups. The density of the δ-opioid receptor in rat brain homogenates was quantified from adulthood down to as early an age as possible by means of saturation binding studies using the δ-receptor-selective antagonist [3H]naltrindole and the δ-receptor-selective agonist [3H]Ile5,6Deltorphin II and by homologous displacement studies using the d-receptor-selective agonist Deltorphin I. δ-binding was measurable at post-natal day 3 and steadily increased to a level not significantly different from adult levels by day 25. Comparison of δ-receptor densities in the brain and spinal cord of the 25-day-old weaned and non-weaned rat showed no difference when measured with [3H]naltrindole or [3H]Ile5,6Deltorphin II. Using [3H]Deltorphin I, the δ-receptor density in the weaned animals was approximately 25% higher than in the non-weaned animals in both tissues. Saturation binding studies in the presence of 100mM Na+, 50μM GMPPNP or both, conditions designed to investigate the possible influence of the G-protein coupled state of the receptors on the ligand binding, were carried out with all three ligands. The only significant difference observed was a 32% decrease in the binding of [3H]Deltorphin I in the weaned animals in the presence of 50μM GMPPNP which did not occur in the non-weaned animals, suggesting that the weaned/non-weaned difference in δ-receptor density seen by [3H]Deltorphin I may be a consequence of different or incomplete G-protein-coupling prior to weaning.

Item Type: Thesis (Doctoral)
Divisions : Theses
Authors : Kelly, Mary D. W.
Date : 1996
Additional Information : Thesis (Ph.D.)--University of Surrey (United Kingdom), 1996.
Depositing User : EPrints Services
Date Deposited : 06 May 2020 12:07
Last Modified : 06 May 2020 12:13
URI: http://epubs.surrey.ac.uk/id/eprint/855752

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year


Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800