Premium
Effects of acute agonist treatment on subcellular distribution of κ opioid receptor in rat spinal cord
Author(s) -
Wang Yulin,
Xu Wei,
Huang Peng,
Chavkin Charles,
Van Bockstaele Elisabeth J.,
LiuChen LeeYuan
Publication year - 2009
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.21971
Subject(s) - dynorphin , dynorphin a , spinal cord , chemistry , agonist , receptor , κ opioid receptor , endocrinology , medicine , opioid , opioid peptide , biology , neuroscience , biochemistry
We investigated whether acute treatment with agonists affected the subcellular distribution of κ opioid receptor (KOPR) in the dorsal horn of the rat lumbar spinal cord by using immunoelectron microscopy. Rats were injected intrathecally (i.t.) with U50,488H (100 nmole), dynorphin A(1–17) (15 nmole), or vehicle. The doses chosen have been shown to induce antinociception. Rats were perfused transcardially 30 min later, and lumbar spinal cords were removed and processed for electron microscopic analysis. KOPR was stained with KT‐2, a specific polyclonal antibody against the rat/mouse KOPR(371–380) peptide, followed by gold‐labeled secondary antibody and silver intensification. The silver grains were present in axons, terminals, dendrites, and somata, and the association with plasma membranes was quantified in dendrites, because KOPR immunoreactivity was most frequently observed in these profiles. In vehicle‐treated rats, ∼27% of KOPR immunoreactivity was associated with plasma membranes. U50,488H, i.t., did not cause a significant change in the percentage of KOPR present on plasma membranes, whereas dynorphin A, i.t., significantly decreased cell surface KOPR to ∼19%. In summary, these data indicate that U50,488H and dynorphin A differentially regulate the subcellular distribution of endogenous KOPR. © 2009 Wiley‐Liss, Inc.