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 (mGluR1, mGluR5) and II (mGluR2, mGluR3) 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). mGluR5 mRNA was up-regulated 5 h and 1 day post-surgery in laminae I–II of the spinal cord dorsal horn. mGluR5 protein was increased 1 day post-surgery. A delayed induction of mGluR2 and mGluR3 mRNAs and mGluR2/3 protein occurred in spinal cord 3 days after surgery. By 6 days, mGluR2 mRNA levels had returned to normal, however, mGluR3 mRNA and mGluR2/3 protein remained elevated. No change was detected in mGluR1. These results demonstrate that mGluRs are differentially regulated following surgery and support a link between mGluR-mediated activity and post-surgical pain.
|Journal||Pain: The Journal of the International Association for the Study of Pain|
|Publication status||Published - 1 Jul 2004|
- differential expression
- metabotropic glutamate receptor
- spinal cord