[Upregulation of P2X3 receptors in dorsal root ganglion of TRPV1 knockout female mice]

Sheng Li Xue Bao. 2014 Aug 25;66(4):431-7.
[Article in Chinese]

Abstract

The study was aimed to investigate the changes in mechanical pain threshold in the condition of chronic inflammatory pain after transient receptor potential vanilloid 1 (TRPV1) gene was knockout. Hind-paw intraplantar injection of complete freund's adjuvant (CFA, 20 μL) produced peripheral inflammation in wild-type and TRPV1 knockout female mice. The mechanical pain thresholds were measured during the 8 days after injection and pre-injection by using Von-Frey hair. Nine days after injection, mice were killed and the differences of expression of c-Fos and P2X3 receptor in the dorsal root ganglia (DRG) and spinal cord dorsal horn were examined by Western blotting between the two groups. Compared with that in wild-type mice, the mechanical pain threshold was increased significantly in TRPV1 knockout mice (P < 0.05); 3 days after CFA injection, the baseline mechanical pain threshold in the TRPV1 knockout mice group was significantly higher than that in the wild-type mice group (P < 0.05); The result of Western blotting showed that the expression of c-Fos protein both in DRG and spinal cord dorsal horn of TRPV1 knockout mice group was decreased significantly compared with that in wild-type mice group (P < 0.01, P < 0.05), while the expression of P2X3 receptor in DRG of TRPV1 knockout mice group was increased significantly compared with that in wild-type mice group (P < 0.05). Our findings indicate that TRPV1 may influence the peripheral mechanical pain threshold by mediating the expression of c-Fos protein both in DRG and spinal cord dorsal horn and changing the expression of P2X3 receptor in DRG.

MeSH terms

  • Animals
  • Female
  • Ganglia, Spinal / metabolism*
  • Mice
  • Mice, Knockout
  • Pain / metabolism*
  • Pain Threshold
  • Proto-Oncogene Proteins c-fos / metabolism
  • Receptors, Purinergic P2X3 / metabolism*
  • Spinal Cord / metabolism
  • TRPV Cation Channels / genetics
  • Up-Regulation

Substances

  • Proto-Oncogene Proteins c-fos
  • Receptors, Purinergic P2X3
  • TRPV Cation Channels
  • TRPV1 receptor