title: Distinct activation of tumor necrosis factor-α and interleukin-6 in             the spinal cord after surgical incision in rats.
abstract: In a previous study, we showed that a deep thoracic incision induces the segmental upregulation of interleukin-1β (IL-1β) in the spinal cord. However, whether the cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) are also activated in response to surgical incision remains to be determined. The present study aimed to investigate the expression pattern of TNF-α and IL-6 in the spinal cord following a deep thoracic incision. After surgical incision, the mRNA levels of TNF-α and IL-6 in the thoracic spinal cord were transiently upregulated as determined by real-time polymerase chain reaction (PCR) assay. However, the activation of IL-6 was detected at 1 h postoperatively, which was earlier compared to that of TNF-α, observed at 6 h postoperatively. The activated TNF-α was mainly localized in the neurons, but not in microglia or astrocytes as determined by immunohistochemistry and confocal microscopy. However, the increased IL-6-immunoreactivity was mainly expressed in blood vessels. The differential upregulation of TNF-α and IL-6 induced by incision suggests that the proinflammatory cytokines may play different roles in the development of surgical pain.
authors.affiliation: Department of Anesthesia, The Second Xiangya Hospital of Central South University, Changsha, Hunan, People's Republic of China.
authors.forename: Yan-Ling
authors.initials: YL
authors.lastname: Zhang
authors.forename: Jun-Mei
authors.initials: JM
authors.lastname: Xu
authors.forename: Pei
authors.initials: P
authors.lastname: Zhou
authors.forename: Xiao-Lin
authors.initials: XL
authors.lastname: Zhong
authors.forename: Ru-Ping
authors.initials: RP
authors.lastname: Dai
mesh_terms: D000818:Animals; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism*; D008297:Male; D009474:Neurons / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013119:Spinal Cord Injuries / Q000378:metabolism* / Q000473:pathology; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D015850:Interleukin-6; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha