Recruitment of opioid peptide-containing neutrophils is independent of formyl peptide receptors

• Published in: Journal of neuroimmunology Vol. 230; no. 1; pp. 65 - 73
• Main Authors: Hackel, D, Stolz, A, Mousa, S.A, Brack, A, Rittner, H.L
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.2011
• Subjects: Allergy and Immunology; Analgesia; Animals; Cell Adhesion Molecules - metabolism; Cell Separation; Flow Cytometry; Fluorescent Antibody Technique; FPR; Male; Mycobacterium; Neurology; Neutrophil; Neutrophil Infiltration - physiology; Neutrophils - metabolism; Opioid Peptides - metabolism; Pain - metabolism; Rats; Rats, Wistar; Receptors, Formyl Peptide - metabolism; Formyl-Met-Leu-Phe; ENK; fMLP; N-t-Boc-Phe-D-Leu-Phe-D-Leu-Phe; Formyl peptide receptor; CXCL2/3; Met-enkephalin; FPR; ICAM-1; CXCL1; Complete Freund's adjuvant; PPT; Intercellular cell adhesion molecule-1; Corticotrophin releasing factor; Keratinocyte derived chemokine; BocFLFLF; β-Endorphin; Paw pressure threshold; Analgesia; Repeated measures analysis of variance; CRF; END; RM ANOVA; Neutrophil; Monocyte inflammatory protein-2; CFA
• ISSN: 0165-5728; 1872-8421
• DOI: 10.1016/j.jneuroim.2010.08.027

Abstract In complete Freund's adjuvans (CFA) inflammation opioid containing neutrophils release opioid peptides upon stimulation and mediate peripheral analgesia. Neutrophil migration is regulated partially by chemokines, but other mediators e.g. formyl peptides could also contribute. In vitro , formyl peptides but not Mycobacterium butyricum (CFA component) induced migration of neutrophils. In contrast, local formyl peptide injection did not induce leukocyte recruitment in vivo due to insufficient up-regulation of adhesion molecule expression. Furthermore, leukocyte recruitment and peripheral opioid-mediated analgesia were unaffected by systemic formyl peptide receptor blockade in CFA inflammation. Thus, while formyl peptides do not regulate migration they directly stimulate opioid peptide release.