Differential expression of central metabotropic glutamate receptor (mGluR) subtypes in a clinical model of post-surgical pain.
Tissue damage during surgery can induce 'central sensitization' and the development of pain and hyperalgesia post-operatively. Metabotropic glutamate receptors (mGluRs) contribute to nociception, inflammatory pain and hyperalgesia. This study characterized the temporal expression of group I (mGluR(1), mGluR(5)) and II (mGluR(2), mGluR(3)) mGluRs in spinal cord following abdominal surgery. Lumbar spinal cord was recovered from adult sheep euthanased 5 h, 1, 2, 3 and 6 days after undergoing a midline laparotomy, and processed for mGluR mRNA (real-time PCR, in situ hybridization) and protein (Western blotting). mGluR(5) mRNA was up-regulated 5 h and 1 day post-surgery in laminae I-II of the spinal cord dorsal horn. mGluR(5) protein was increased 1 day post-surgery. A delayed induction of mGluR(2) and mGluR(3) mRNAs and mGluR(2/3) protein occurred in spinal cord 3 days after surgery. By 6 days, mGluR(2) mRNA levels had returned to normal, however, mGluR(3) mRNA and mGluR(2/3) protein remained elevated. No change was detected in mGluR(1). These results demonstrate that mGluRs are differentially regulated following surgery and support a link between mGluR-mediated activity and post-surgical pain.
Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow G4 0BA, UK. sharron.dolan@gcal.ac.uk
Sharron
S
Dolan
James G
JG
Kelly
Ana M
AM
Monteiro
Andrea M
AM
Nolan
D000818:Animals; D015153:Blotting, Western / Q000379:methods; D004195:Disease Models, Animal; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D017403:In Situ Hybridization / Q000379:methods; D007813:Laparotomy / Q000379:methods; D010149:Postoperative Pain / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D018094:Receptors, Metabotropic Glutamate / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012756:Sheep; D013116:Spinal Cord / Q000378:metabolism*; D013997:Time Factors
D012333:RNA, Messenger; D018094:Receptors, Metabotropic Glutamate