Release of opioid peptides from the spinal cord of rats subjected to chronic pain.
Chronic localized pain increased the level of the opioid peptides, dynorphin (DYN), alpha-neoendorphin (ANEO), Met-enkephalin (MET) and Mets-enkephalin-Arg6-Gly7-Leu8 (MEAGL), in the lumbar enlargement of the rat spinal cord. It was accompanied with a reduction of the spontaneous and K+-stimulated release of ANEO and MEAGL from spinal cord slices in vitro and a decreased release of ANEO from the spinal cord in vivo. The results indicate that the reduction in the activity of endogenous opioid peptide systems might occur in the spinal cord of rats subjected to chronic pain.
D000818:Animals; D001169:Arthritis, Experimental / Q000503:physiopathology; D002908:Chronic Disease; D004723:Endorphins / Q000378:metabolism*; D008297:Male; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains; D013116:Spinal Cord / Q000378:metabolism* / Q000503:physiopathology
D004723:Endorphins