title: Running exercise alleviates pain and promotes cell proliferation in a rat model of intervertebral disc degeneration.
abstract: Chronic low back pain accompanied by intervertebral disk degeneration is a common musculoskeletal disorder. Physical exercise, which is clinically recommended by international guidelines, has proven to be effective for degenerative disc disease (DDD) patients. However, the mechanism underlying the analgesic effects of physical exercise on DDD remains largely unclear. The results of the present study showed that mechanical withdrawal thresholds of bilateral hindpaw were significantly decreased beginning on day three after intradiscal complete Freund's adjuvant (CFA) injection and daily running exercise remarkably reduced allodynia in the CFA exercise group beginning at day 28 compared to the spontaneous recovery group (controls). The hindpaw withdrawal thresholds of the exercise group returned nearly to baseline at the end of experiment, but severe pain persisted in the control group. Histological examinations performed on day 70 revealed that running exercise restored the degenerative discs and increased the cell densities of the annulus fibrosus (AF) and nucleus pulposus (NP). Furthermore, immunofluorescence labeling revealed significantly higher numbers of 5-bromo-2-deoxyuridine (BrdU)-positive cells in the exercise group on days 28, 42, 56 and 70, which indicated more rapid proliferation compared to the control at the corresponding time points. Taken together, these results suggest that running exercise might alleviate the mechanical allodynia induced by intradiscal CFA injection via disc repair and cell proliferation, which provides new evidence for future clinical use.
authors.affiliation: Department of Rehabilitation Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China. luanshuo126@163.com.
authors.forename: Shuo
authors.initials: S
authors.lastname: Luan
authors.affiliation: Department of Rehabilitation Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China. wanqing_2012@163.com.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wan
authors.affiliation: Department of Rehabilitation Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China. rogerluohj@163.com.
authors.forename: Haijie
authors.initials: H
authors.lastname: Luo
authors.affiliation: Department of Rehabilitation Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China. lixiao204011987@sina.com.
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Rehabilitation Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China. songjian112626@163.com.
authors.forename: Songjian
authors.initials: S
authors.lastname: Ke
authors.affiliation: Department of Rehabilitation Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China. lincaina826@126.com.
authors.forename: Caina
authors.initials: C
authors.lastname: Lin
authors.affiliation: Department of Rehabilitation Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China. wyy_98@126.com.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Rehabilitation Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China.
authors.forename: Shaoling
authors.initials: S
authors.lastname: Wu
authors.affiliation: Department of Rehabilitation Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China. ma_chao99@126.com.
authors.forename: Chao
authors.initials: C
authors.lastname: Ma
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000378:metabolism; D002452:Cell Count; D049109:Cell Proliferation; D004195:Disease Models, Animal; D005620:Freund's Adjuvant; D006930:Hyperalgesia / Q000139:chemically induced / Q000473:pathology / Q000628:therapy; D055959:Intervertebral Disc Degeneration / Q000473:pathology* / Q000503:physiopathology*; D008297:Male; D010146:Pain / Q000473:pathology* / Q000503:physiopathology*; D010805:Physical Conditioning, Animal; D017207:Rats, Sprague-Dawley; D012420:Running; D013997:Time Factors
chemical_list: D005620:Freund's Adjuvant; D001973:Bromodeoxyuridine