Induction of CB2 receptor expression in the rat spinal cord of neuropathic but not inflammatory chronic pain models.
Cannabinoids have been considered for some time as potent therapeutic agents in chronic pain management. Central and systemic administration of natural, synthetic and endogenous cannabinoids produce antinociceptive and antihyperalgesic effects in both acute and chronic animal pain models. Although much of the existing data suggest that the analgesic effects of cannabinoids are mediated via neuronal CB1 receptors, there is increasing evidence to support a role for peripheral CB2 receptors, which are expressed preferentially on immune cells. As yet, little is known about the central contribution of CB2 in neuropathic pain states. We report here that chronic pain models associated with peripheral nerve injury, but not peripheral inflammation, induce CB2 receptor expression in a highly restricted and specific manner within the lumbar spinal cord. Moreover, the appearance of CB2 expression coincides with the appearance of activated microglia.
Zhang
Ji
J
AstraZeneca R&D, Montréal, 7171, Frederick-Banting, Ville St-Laurent, Quebec, H4S 1Z9, Canada.
Hoffert
Cyrla
C
Vu
Huy Khang
HK
Groblewski
Thierry
T
Ahmad
Sultan
S
O'Donnell
Dajan
D
D000818:Animals; D015703:Antigens, CD; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D030161:Avian Proteins; D051926:Basigin; D001798:Blood Proteins; D018845:CD11 Antigens / Q000378:metabolism; D004195:Disease Models, Animal; D053331:Ectodysplasins; D005620:Freund's Adjuvant / Q000008:administration & dosage; D015870:Gene Expression; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007249:Inflammation / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D017628:Microglia / Q000378:metabolism / Q000473:pathology; D010146:Pain / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D043885:Receptor, Cannabinoid, CB2; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug / Q000235:genetics / Q000378:metabolism*; D020426:Sciatic Neuropathy / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D013119:Spinal Cord Injuries / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D013997:Time Factors
D015703:Antigens, CD; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D030161:Avian Proteins; D001798:Blood Proteins; C102624:Bsg protein, Gallus gallus; C079432:Bsg protein, rat; D018845:CD11 Antigens; C469526:Cnr2 protein, rat; D053331:Ectodysplasins; D005904:Glial Fibrillary Acidic Protein; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D012333:RNA, Messenger; D043885:Receptor, Cannabinoid, CB2; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug; D051926:Basigin; D005620:Freund's Adjuvant