title: Effects of serum immunoglobulins from patients with complex regional pain syndrome (CRPS) on depolarisation-induced calcium transients in isolated dorsal root ganglion (DRG) neurons.
abstract: Complex regional pain syndrome (CRPS) is thought to have an auto-immune component. One such target recently proposed from the effects of auto-immune IgGs on Ca(2+) transients in cardiac myocytes and cell lines is the α1-adrenoceptor. We have tested whether such IgGs exerted comparable effects on nociceptive sensory neurons isolated from rat dorsal root ganglia. Depolarisation-induced [Ca(2+)]i transients were generated by applying 30 mM KCl for 2 min and monitored by Fura-2 fluorescence imaging. No IgGs tested (including 3 from CRPS patients) had any significant effect on these [Ca(2+)]i transients. However, IgG from one CRPS patient consistently and significantly reduced the K(+)-induced response of cells that had been pre-incubated for 24h with a mixture of inflammatory mediators (1 μM histamine, 5-hydroxytryptamine, bradykinin and PGE2). Since this pre-incubation also appeared to induce a comparable inhibitory response to the α1-agonist phenylephrine, this is compatible with the α1-adrenoceptor as a target for CRPS auto-immunity. A mechanism whereby this might enhance pain is suggested.
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Reilly
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK; Pain Research Institute, Department of Translational Medicine, University of Liverpool, Liverpool, L9 7AL, UK.
authors.forename: Backialakshmi
authors.initials: B
authors.lastname: Dharmalingam
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Marsh
authors.affiliation: Pain Research Institute, Department of Translational Medicine, University of Liverpool, Liverpool, L9 7AL, UK.
authors.forename: Victoria
authors.initials: V
authors.lastname: Thompson
authors.affiliation: Pain Research Institute, Department of Translational Medicine, University of Liverpool, Liverpool, L9 7AL, UK. Electronic address: andreasgoebel@rocketmail.com.
authors.forename: Andreas
authors.initials: A
authors.lastname: Goebel
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
authors.forename: David A
authors.initials: DA
authors.lastname: Brown
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects*; D002478:Cells, Cultured; D020918:Complex Regional Pain Syndromes / Q000097:blood* / Q000276:immunology*; D005260:Female; D005727:Ganglia, Spinal / Q000166:cytology*; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology*; D008297:Male; D009474:Neurons / Q000187:drug effects*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D007074:Immunoglobulin G; D011188:Potassium; D002118:Calcium
keywords: Auto-immunity; Calcium; Complex regional pain syndrome; Immunoglobulin; Sensory neurons