Enhanced expression of constitutive endothelial nitric oxide synthase by astrocytes in the spinal cords of rats with experimental autoimmune encephalomyelitis.

To investigate the expression of eNOS in a disease affecting the CNS, we induced EAE and analyzed the expression of eNOS by Western blot analysis and immunohistochemistry. Western blot analysis indicated that eNOS increased substantially in the spinal cords of rats with EAE compared with the spinal cords of normal and adjuvant sensitized rats. Immunohistochemistry revealed that eNOS was positive for some macrophages and astrocytes in EAE lesions. The vascular endothelial cells in EAE lesions also showed a light increase of eNOS immunoreactivity. This trial demonstrated that eNOS is increased in the diseased EAE spinal cord and that the source of eNOS is from the exogenous inflammatory cells and from the endogenous spinal cord cells including astrocytes.