Phosphorylation of caveolin-1 occurs during cell activation by various stimuli. In this study, the involvement of caveolin-1 in an irradiation injured spinal cord was examined by analyzing the phosphorylation of caveolin-1 in the spinal cord of rats after irradiation with a single dose of 15 Gray from a (60)Co gamma-ray source at 24 h post-irradiation (PI). A Western blot analysis showed that the phosphorylated form of caveolin-1 (p-caveolin-1) was expressed constitutively in the normal spinal cords and was significantly higher in the spinal cord of irradiated rats at 24 h PI. The increased expression of ED1, which is a marker of activated microglia/macrophages, was matched with that of p-caveolin-1. In the irradiated spinal cords, there was a higher level of p-caveolin-1 immunoreactivity in the isolectin B4-positive microglial, ependymal, and vascular endothelial cells, in which p-caveolin-1 was weakly and constitutively expressed in the normal control spinal cords. These results suggest that total body irradiation induces activation of microglial cells in the spinal cord through the phosphorylation of caveolin-1.
Animals ; Blotting, Western/veterinary ; Caveolin 1/*metabolism ; Gene Expression Regulation/*radiation effects ; Immunohistochemistry/veterinary ; Male ; Phosphorylation/radiation effects ; Rats ; Rats, Sprague-Dawley ; Spinal Cord/physiopathology/*radiation effects ; Spinal Cord Injuries/physiopathology/*veterinary

OBJECTIVETo evaluate the effect of local X-irradiation on spinal cord injury by using physiology, kinology, electrophysiology and histology method.

METHODS46 female Sprague-Dawley rats were subjected to spinal cord injury by weight dropping on T(11-12). All animals were divided into 3 groups randomly. One of the animal groups was irradiated with 10 Gy at the lesion site; another was irradiated with 20 Gy, the other without irradiation is regarded as sham-group. The animals were euthanized at different time points at 4 and 12 weeks after irradiation. Spinal cord callus was assessed by using physiology, kinology, and electrophysiology and histology method.

RESULTSIn all the groups, the NF at 14 weeks were found higher than that of 6 weeks. Both 10 Gy irradiated and 20 Gy irradiated groups were higher than those of group at each time point (P < 0.05). The MBP decreased at 14 weeks in irradiated groups (P < 0.05), but increased at 14 weeks in sham-group (P < 0.05), the MBP of irradiated groups was lower than that sham-group at 14 weeks (P < 0.05). The GFAP and Nogo-A at 14 weeks were higher than that in 6 weeks in all the groups (P < 0.05), and there was no statistical significance with physiology, kinology, electrophysiology test in all groups.

CONCLUSIONA self-repair mechanism exists after SCI, which will last at least 14 weeks. Local irradiation promotes the regeneration of spinal cord system after injury to some extent.

Animals ; Disease Models, Animal ; Female ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Spinal Cord ; pathology ; physiopathology ; radiation effects ; Spinal Cord Injuries ; pathology ; physiopathology ; radiotherapy ; X-Rays

OBJECTIVETo explore whether X-irradiation can enhance the functional and structural recovery of the injured spinal cord of rats.

METHODSSeventy Sprague-Dawley rats received spinal cord injury by clip compression at the T2 level were randomly divided into two groups. The experimental group received X-irradiation at 14 days after injury, the control group did not receive X-irradiation. The functional tests were performed at day 3, 7, 14, 21, 28, 35, and 42 after irradiation including open field movement, inclined plane and pain withdrawal test. All injured rats were sacrificed at 43 days after injury and the injured spinal cords were taken out for histological tests.

RESULTSSixty-two rats met the experimental requirements among 70 injured rats, 32 rats in experimental group and 30 rats in control group. Statistically significant difference was achieved between two groups in open field movement and inclined plane (P < 0.01), but not for the pain withdrawal test. The edema and necrosis area of injured spinal cords of experimental group were less than those in control group, and the number of axons of experimental group were more than those in control group.

CONCLUSIONSX-irradiation can enhance the functional recovery by improving and restoring structural integrity of the injured spinal cord.

Animals ; Axons ; pathology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Recovery of Function ; Spinal Cord ; pathology ; physiopathology ; radiation effects ; Spinal Cord Injuries ; pathology ; physiopathology ; radiotherapy

OBJECTIVETo test the hypothesis that delayed X-irradiation can enhance the functional and structural recovery of the injured spinal cord in rats.

METHODSSeventy Sprague-Dawley rats were randomly divided into two groups, 35 rats in each. The control group sustained a one-minute clip compression (force of clip was 30 g) injury of the spinal cord at the T2 level, without X-irradiation. The experimental group received X-irradiation 14 days after injury. Neurological function was assessed by the modified Tarlov method, including hind limbs movement, inclined plane, and pain withdrawal. These tests were performed in a blinded fashion at 3, 7, 14, 21, 28, 35, and 42 days after injury. At 43 days after injury, histological examination of the injured spinal cord was performed following decapitation of the rats.

RESULTSSixty-two rats met the experimental requirements (spinal cord injury was similar), 32 rats in experimental group and 30 rats in control group. Statistically significant difference was observed between the two groups in hind limbs movement and inclined plane (P < 0.01), but not in the pain withdrawal test. The edema and necrosis areas of injured spinal cords in experimental group were less than those in control group, and axons in experimental group were significantly more than those in control group (P < 0.01).

CONCLUSIONDelayed X-irradiation following spinal cord injury may enhance functional recovery by improving and restoring structural integrity of the injured spinal cord in rats.

Animals ; Axons ; physiology ; radiation effects ; Hindlimb ; Joints ; physiology ; Motor Activity ; Movement ; Radiotherapy ; methods ; Rats ; Rats, Sprague-Dawley ; Spinal Cord ; physiopathology ; radiation effects ; Spinal Cord Injuries ; radiotherapy ; rehabilitation ; Weight-Bearing ; X-Rays