Intrathecal CART (55-102) attenuates hyperlagesia and allodynia in a mouse model of neuropathic but not inflammatory pain.
CART peptides are found in brain and spinal cord areas involved in pain transmission. In the present study, we investigated the role of rat CART (55-102) in the modulation of chronic pain using models of chronic neuropathic (nerve injury model) and inflammatory (carrageenan test) pain models in the mouse after intrathecal administration. The results show that CART (55-102) was highly effective in reversing the hyperalgesia and allodynia signs of chronic neuropathic pain in a dose-related manner at doses (0.05-2 microg/mouse) that did not affect motor coordination of the animals. These effects lasted for at least 3 h after injection and were not blocked by naloxone, an opiate antagonist. Although CART (55-102) attenuated carrageenan-induced hyperalgesia, it failed to reduce the inflammation associated with this model. These results suggest the involvement of the CART peptides in the development of hyperalgesia and allodynia associated with neuropathic pain.
Damaj
M Imad
MI
Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Box 980613, Richmond, VA 23298-0613, USA. mdamaj@hsc.vcu.edu
Zheng
Jianfeng
J
Martin
Billy R
BR
Kuhar
Michael J
MJ
D000818:Animals; D002351:Carrageenan; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D006930:Hyperalgesia / Q000188:drug therapy*; D007249:Inflammation / Q000139:chemically induced / Q000188:drug therapy; D051379:Mice; D008813:Mice, Inbred ICR; D009043:Motor Activity / Q000187:drug effects; D009419:Nerve Tissue Proteins; D010146:Pain / Q000139:chemically induced / Q000188:drug therapy*; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D013997:Time Factors; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein
D002351:Carrageenan; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; C428723:cocaine- and amphetamine-regulated transcript protein (55-102); D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein