Immunohistochemical localization of endomorphin-1 and endomorphin-2 in immune cells and spinal cord in a model of inflammatory pain

Title

Immunohistochemical localization of endomorphin-1 and endomorphin-2 in immune cells and spinal cord in a model of inflammatory pain

Creator

Mousa SA; Machelska H; Schafer M; Stein C

Publisher

Journal Of Neuroimmunology

Date

2002

Subject

Male; Animals; Rats; Biomarkers of Pain; Immunohistochemistry; Freund's Adjuvant; Hindlimb; Wistar; Lymph Nodes/cytology; Lymphocytes/chemistry; Macrophages/chemistry; Monocytes/chemistry; Oligopeptides/analysis; Pain/chemically induced/immunology; Posterior Horn Cells/chemistry; Skin/chemistry/immunology/innervation

Description

Recently, two novel highly selective mu-opioid receptor (MOR) agonists, endomorphin-1 and endomorphin-2, have been isolated from bovine as well as human brains and were proposed to be the endogenous ligand for MOR. Later, endomorphin-1 and endomorphin-2 have been detected in the immune system of rats and humans using radioimmunoassay in combination with reverse-high-phase-liquid chromatography. In the present study, we analyzed the expression of endomorphin-1, endomorphin-2 and MOR by immunohistochemistry in a model of Freund's complete adjuvant (FCA)-induced painful inflammation. While MOR was upregulated on peripheral and central nerve terminals, inflammation did not alter endomorphin-2 expression in nerve fibers either in the dorsal horn of the spinal cord or in subcutaneous tissue. Endomorphin-1 and endomorphin-2 were expressed in immune cells (macrophage/monocytes) in the medullary region of the popliteal lymph nodes. The proportion of immunocytes (macrophage/monocytes, lymphocytes) containing endomorphin-1 and endomorphin-2 was increased in inflamed lymph nodes and subcutaneous paw tissue of animals with local inflammatory pain. Taken together, the upregulation of MOR and of its endogenous ligands endomorphin-1 and endomorphin-2 in immunocytes suggests an involvement of these opioid peptides in the peripheral control of inflammatory pain.
2002

Rights

Article information provided for research and reference use only. PedPalASCNET does not hold any rights over the resource listed here. All rights are retained by the journal listed under publisher and/or the creator(s).

Type

Journal Article

Citation List Month

Backlog

Pages

5-15

Issue

1

Volume

126

Citation

Mousa SA; Machelska H; Schafer M; Stein C, “Immunohistochemical localization of endomorphin-1 and endomorphin-2 in immune cells and spinal cord in a model of inflammatory pain,” Pediatric Palliative Care Library, accessed November 28, 2021, https://pedpalascnetlibrary.omeka.net/items/show/13025.

Social Bookmarking