Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8867
pubmed:dateCreated
1993-8-26
pubmed:abstractText
Opioids produce analgesia by interacting with local opioid receptors in peripheral inflamed tissue. This study investigated whether endogenous ligands of these receptors are present in synovia and whether such opioid peptides can inhibit pain by activation of intra-articular opioid receptors. Samples of synovium from 8 patients undergoing arthroscopic knee surgery were examined by immunohistochemistry for the presence of beta-endorphin, met-enkephalin, and dynorphin. All tissue samples showed synovitis. Inflammatory cells stained strongly for beta-endorphin and met-enkephalin but not for dynorphin. To find out whether blockade of intra-articular opioid receptors affected pain, we randomly assigned 22 patients undergoing arthroscopic knee surgery to receive naloxone (0.04 mg) intra-articularly (n = 10) or intravenously (n = 12); each patient received a placebo injection into the other site. Postoperative pain was assessed by visual analogue scale, a numerical rating scale, the McGill pain questionnaire, and supplementary analgesic consumption during the next 24 h. All pain scores were higher in the intra-articular naloxone group than in the intravenous naloxone group. The differences were significant (p < 0.05) during the first 4 h. Supplementary analgesic consumption was significantly higher in the intra-articular group (52.5 [14.0] vs 15.6 [8.0] mg diclofenac, p < 0.05). Opioid peptides are present in inflamed synovial tissue and can inhibit pain after knee surgery through an action specific to intra-articular opioid receptors. These findings expand the gate control theory of pain and suggest new approaches such as the development of peripherally acting opioid analgesics without central side-effects.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0140-6736
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
342
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
321-4
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed-meshheading:8101583-Adult, pubmed-meshheading:8101583-Aged, pubmed-meshheading:8101583-Arthroscopy, pubmed-meshheading:8101583-Double-Blind Method, pubmed-meshheading:8101583-Dynorphins, pubmed-meshheading:8101583-Endorphins, pubmed-meshheading:8101583-Enkephalin, Methionine, pubmed-meshheading:8101583-Humans, pubmed-meshheading:8101583-Immunohistochemistry, pubmed-meshheading:8101583-Injections, Intra-Articular, pubmed-meshheading:8101583-Injections, Intravenous, pubmed-meshheading:8101583-Knee Joint, pubmed-meshheading:8101583-Middle Aged, pubmed-meshheading:8101583-Naloxone, pubmed-meshheading:8101583-Pain, Postoperative, pubmed-meshheading:8101583-Receptors, Opioid, pubmed-meshheading:8101583-Synovial Membrane, pubmed-meshheading:8101583-Synovitis, pubmed-meshheading:8101583-beta-Endorphin
pubmed:year
1993
pubmed:articleTitle
Local analgesic effect of endogenous opioid peptides.
pubmed:affiliation
Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland.
pubmed:publicationType
Journal Article, Clinical Trial, Randomized Controlled Trial