Immunohistochemical analysis of iNOS after acute spinal cord injury

Objective To investigate the significance of inducible nitric oxide synthase (iNOS) expression after acute spinal cord injury in rats.Methods The incomplete spinal cord injury ( SCI ) model in T_ 9 segment was established according to modified Gruner method, using immunohistochemical and Western blot analysis to detect the activity of iNOS at 4 h, 1 d, 3 d, 7 d and 14 d respectively after SCI.Results Immunohistochemistry showed that the expression of iNOS was at very low level (4.34±1.15)% in normal spinal cord, while it increased from 24 h after SCI and reached the summit at 7 d with the number of (9.03±3.73)% (P0.05) and (47.57±8.62)% (P0.01), respectively. Western blot analysis indicated that the scanning strap was weak in normal spinal cord,but gradually reinforced at 24 h and reached the maximum at 7 d after SCI.Conclusion The data indicate that iNOS may play an important role in the secondary inflammation after spinal cord injury rather than in physiological process.