title: Incline treadmill exercise suppresses pain hypersensitivity associated with the modulation of pro-inflammatory cytokines and anti-inflammatory cytokine in rats with peripheral nerve injury.
abstract: We aimed to investigate the impact of 3 weeks of incline treadmill exercise (TE) on withdrawal responses elicited by thermal and mechanical stimuli, and on anti-inflammatory cytokine (interleukin-10, IL-10) and pro-inflammatory cytokines (IL-6 and tumor necrosis factor-alpha [TNF-α]) expression in the sciatic nerve of rats underwent chronic constriction injury (CCI). Group 1 received a sham-operation where the sciatic nerve was exposed but not ligated, while Group 2 underwent a sham-operation followed by exercising on an 8%-incline treadmill (TE8). Group 3 underwent only the CCI procedure, and Groups 4 and 5 underwent the CCI procedure followed by exercising on an 0%-incline treadmill (TE0) and TE8, respectively. Mechanical and thermal sensitivity and protein expression of IL-10, IL-6 and TNF-α were evaluated on postoperative days 12 and 26. Among the five groups, Group 5 displayed the least weight gain. Compared with Group 3, Group 5 had smaller decreases in mechanical withdrawal thresholds and heat withdrawal latencies. The CCI rats who received TE at 8% incline showed the downregulation of TNF-α and IL-6 in their sciatic nerves on postoperative days 12 and 26, as was found in the Group 3 rats. TE at 8% incline also prevented the downregulation of IL-10 in their sciatic nerves on postoperative day 12. The results demonstrated that increased incline improves the anti-nociceptive effects of treadmill running. Inclined exercise reduces the levels of pro-inflammatory cytokines and increases the level of an anti-inflammatory cytokine.
authors.affiliation: Department of Physical Therapy, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Kun-Ling
authors.initials: KL
authors.lastname: Tsai
authors.affiliation: Department of Physical Therapy, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Po-Ching
authors.initials: PC
authors.lastname: Huang
authors.affiliation: Department of Anesthesiology, Chi Mei Medical Center, Tainan, Taiwan.
authors.forename: Li-Kai
authors.initials: LK
authors.lastname: Wang
authors.affiliation: Department of Physical Therapy, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Institute of Allied Health Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Ching-Hsia
authors.initials: CH
authors.lastname: Hung
authors.affiliation: Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan; Department of Physical Therapy and Graduate Institute of Rehabilitation Science, College of Health Care, China Medical University, Taichung, Taiwan. Electronic address: cywhwok@mail.cmu.edu.tw.
authors.forename: Yu-Wen
authors.initials: YW
authors.lastname: Chen
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D016207:Cytokines / Q000378:metabolism*; D006930:Hyperalgesia / Q000188:drug therapy / Q000378:metabolism; D008297:Male; D017288:Pain Threshold; D059348:Peripheral Nerve Injuries / Q000188:drug therapy / Q000378:metabolism*; D010805:Physical Conditioning, Animal; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000293:injuries
chemical_list: D000893:Anti-Inflammatory Agents; D016207:Cytokines
keywords: Incline treadmill running; Interleukin-10; Interleukin-6; Mechanical allodynia; Thermal hyperalgesia; Tumor necrosis factor-α