Co-expression of beta-endorphin with adhesion molecules in a model of inflammatory pain.
Opioid-containing immunocytes migrate to inflamed sites where they release beta-endorphin which activates peripheral opioid receptors and produces analgesia. The immigration of immunocytes to sites of inflammation is mediated by adhesion molecules. In this study, the expression of L-, P-, E-selectin and platelet-endothelial adhesion molecule-1 (PECAM-1) in relation to beta-endorphin expression was analyzed by immunohistochemistry in inflamed tissues. The proportion of immunocytes expressing L-selectin was increased in inflamed lymph nodes and subcutaneous paw tissue. P-selectin and PECAM-1 were constitutively expressed on endothelia of noninflamed lymph nodes and subcutaneous tissue and were upregulated in inflammation. beta-endorphin positive cells expressed L-selectin in lymph nodes and subcutaneous tissue. Upregulation of P-selectin and PECAM-1 and the co-localization of L-selectin and beta-endorphin in immunocytes suggest an important role of these adhesion molecules for the recruitment of immunocytes containing beta-endorphin to sites of painful inflammation.
Mousa
S A
SA
Klinik für Anaesthesiologie und operative Intensivmedizin, Freie Universität Berlin, Hindenburgdamm 30, D 12200, Berlin, Germany. Shaaban@zop-admin.ukbf.fu-berlin.de
Machelska
H
H
Schäfer
M
M
Stein
C
C
D000818:Animals; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002634:Chemotaxis, Leukocyte / Q000187:drug effects; D004195:Disease Models, Animal; D019040:E-Selectin / Q000378:metabolism; D005620:Freund's Adjuvant / Q000494:pharmacology; D006614:Hindlimb / Q000187:drug effects / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D007249:Inflammation / Q000139:chemically induced / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D019041:L-Selectin / Q000378:metabolism; D008198:Lymph Nodes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D008297:Male; D019007:P-Selectin / Q000378:metabolism; D010146:Pain / Q000139:chemically induced / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000187:drug effects / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D015854:Up-Regulation / Q000187:drug effects; D001615:beta-Endorphin / Q000378:metabolism*
D015815:Cell Adhesion Molecules; D019040:E-Selectin; D019007:P-Selectin; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D019041:L-Selectin; D001615:beta-Endorphin; D005620:Freund's Adjuvant