title: X-irradiation of the contusion site improves locomotor and histological outcomes in spinal cord-injured rats.
abstract: We have determined whether X-irradiation of the injury site can oppose tissue loss and improve recovery of locomotor function following contusion injury of the spinal cord. Contusion injury was produced in rats at the level of T10 with a weight drop device. Localized X-irradiation (20 Gy) of the injury site was performed at 20 min and 1, 2, 4, 7, and 17 days postinjury. Locomotor recovery was then determined with the 21-point Basso, Beattie, and Bresnahan (BBB) scale. X-irradiation enhanced recovery of locomotor function during a subsequent 6-week observation period when administered 20 min and 1 or 2 days following contusion injury (final BBB score approximately 7-8). X-irradiation at 4-17 days postinjury did not significantly affect final locomotor scores compared with unirradiated rats (final BBB score approximately 2), in marked contrast to previous studies where X-irradiation applied only at 17-18 days benefitted transection injury. The extent of recovery was directly related to measurements of sparing of spinal cord tissue at the contusion center. Because the treatment time window occurred earlier in contusion than reported for transection injury, the results suggest that contusion injury rapidly initiates underlying radiation-sensitive processes that occur only following a delay of several weeks after transection injury. Further optimization of X-ray treatment may lead to a useful therapeutic modality for use in spinal cord contusion injury.
authors.affiliation: Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York 10595, USA. Zeman@nymc.edu
authors.forename: R J
authors.initials: RJ
authors.lastname: Zeman
authors.forename: Y
authors.initials: Y
authors.lastname: Feng
authors.forename: H
authors.initials: H
authors.lastname: Peng
authors.forename: P F
authors.initials: PF
authors.lastname: Visintainer
authors.forename: C R
authors.initials: CR
authors.lastname: Moorthy
authors.forename: W T
authors.initials: WT
authors.lastname: Couldwell
authors.forename: J D
authors.initials: JD
authors.lastname: Etlinger
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000528:radiation effects; D001835:Body Weight / Q000528:radiation effects; D004195:Disease Models, Animal; D005260:Female; D009043:Motor Activity / Q000528:radiation effects*; D018482:Muscle, Skeletal / Q000473:pathology; D009929:Organ Size / Q000528:radiation effects; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function / Q000528:radiation effects; D013116:Spinal Cord / Q000473:pathology / Q000503:physiopathology / Q000528:radiation effects; D013119:Spinal Cord Injuries / Q000473:pathology / Q000503:physiopathology / Q000532:radiotherapy*; D013997:Time Factors; D016896:Treatment Outcome; D014965:X-Rays