title: P2X7 receptor mediates activation of microglial cells in prostate of chemically irritated rats.
abstract: OBJECTIVE
  Evidence shows that adenosine triphosphate (ATP) is involved in the transmission of multiple chronic pain via P2X7 receptor. This study was to investigate the P2X7 and microglial cells in the chronic prostatitis pain.
  
  
  METHODS
  Rats were divided into control group and chronic prostatitis group (n = 24 per group). A chronic prostatitis animal model was established by injecting complete Freund's adjuvant (CFA) to the prostate of rats, and the thermal withdrawal latency (TWL) was detected on days 0, 4, 12 and 24 (n = 6 at each time point in each group). Animals were sacrificed and the pathological examination of the prostate, detection of mRNA expression of P2X7 and ionized calcium binding adaptor molecule 1 (IBA-1) and measurement of content of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the dorsal horn of L5-S2 spinal cord were performed on days 0, 4, 12 and 24. In addition, the content of TNF-α and IL-1β in the dorsal horn of L5-S2 spinal cord was measured after intrathecal injection of inhibitors of microglial cells and/or P2X7 for 5 days.
  
  
  RESULTS
  The chronic prostatitis was confirmed by pathological examination. The expression of P2X7 and IBA-1 and the content of TNF-α and IL-1β in rats with chronic prostatitis were significantly higher than those in the control group. On day 4, the expressions of pro-inflammatory cytokines became to increase, reaching a maximal level on day 12 and started to reduce on day 24, but remained higher than that in the control group. Following suppression of microglial cells and P2X7 receptor, the secretion of TNF-α and IL-1β was markedly reduced.
  
  
  CONCLUSIONS
  In chronic prostatitis pain, the microglial cells and P2X7 receptor are activated resulting in the increased expression of TNF-α and IL-1β in the L5-S2 spinal cord, which might attribute to the maintenance and intensification of pain in chronic prostatitis.
authors.affiliation: Department of Urology; Department of Pathology and Department of Neurobiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Heng
authors.initials: H
authors.lastname: Zhang
authors.forename: Limei
authors.initials: L
authors.lastname: Liu
authors.forename: Zhong
authors.initials: Z
authors.lastname: Yang
authors.forename: Jinhong
authors.initials: J
authors.lastname: Pan
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Chen
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fang
authors.forename: Weibin
authors.initials: W
authors.lastname: Li
authors.forename: Longkun
authors.initials: L
authors.lastname: Li
authors.forename: Gengsheng
authors.initials: G
authors.lastname: Lu
authors.forename: Zhansong
authors.initials: Z
authors.lastname: Zhou
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism; D059350:Chronic Pain / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D008297:Male; D008840:Microfilament Proteins / Q000378:metabolism; D017628:Microglia / Q000166:cytology* / Q000378:metabolism*; D010147:Pain Measurement; D011467:Prostate / Q000378:metabolism* / Q000473:pathology; D011472:Prostatitis / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis; D011897:Random Allocation; D051381:Rats; D058486:Receptors, Purinergic P2X7 / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013116:Spinal Cord / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: C100745:Aif1 protein, rat; D002135:Calcium-Binding Proteins; D053583:Interleukin-1beta; D008840:Microfilament Proteins; D012333:RNA, Messenger; D058486:Receptors, Purinergic P2X7; D014409:Tumor Necrosis Factor-alpha; D000255:Adenosine Triphosphate