title: [Upregulation of P2X3 receptors in dorsal root ganglion of TRPV1 knockout female mice].
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.
authors.affiliation: Department of Physiology, Secondary Military Medical University, Shanghai 200433, China; Department of Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. mabei08@aliyun.com.
authors.forename: Xiao
authors.initials: X
authors.lastname: Fang
authors.forename: Xiao-Han
authors.initials: XH
authors.lastname: Shi
authors.forename: Li-Bin
authors.initials: LB
authors.lastname: Huang
authors.forename: Wei-Fang
authors.initials: WF
authors.lastname: Rong
authors.forename: Bei
authors.initials: B
authors.lastname: Ma
mesh_terms: D000818:Animals; D005260:Female; D005727:Ganglia, Spinal / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D010146:Pain / Q000378:metabolism*; D017288:Pain Threshold; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D058477:Receptors, Purinergic P2X3 / Q000378:metabolism*; D013116:Spinal Cord / Q000378:metabolism; D050916:TRPV Cation Channels / Q000235:genetics; D015854:Up-Regulation
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D058477:Receptors, Purinergic P2X3; D050916:TRPV Cation Channels; C494484:TRPV1 receptor