Gene expression of two kinds of constitutive nitric oxide synthase in injured spinal cord tissue.

OBJECTIVE: To investigate the gene expression of two kinds of constitutive nitric oxide synthase (cNOS): neuronal NOS (nNOS) and endothelial NOS (eNOS) in injured spinal cord tissue. METHODS: Thirty-six adult Sprague-Dawley rats were divided randomly into six groups: the normal group and the injury groups (2, 6, 12, 24, 48 h after injury, respectively). A compression injury model of the spinal cord wa s ma de and gene expression of nNOS and eNOS were examined by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The gene expression of nNOS and eNOS was detected in the normal group and they were up-regulated quickly after injury, reaching the maximum at 6 h. There was no difference between gene expression of nNOS and eNO S in the normal group, but in each injury group the gene expression of eNOS was much higher than that of nNOS. CONCLUSIONS: Expression of constitutive NOS (cNOS) in spinal co rd tissue was up-regulated after injury mainly in the early stage. cNOS as a wh ole offers protection in spinal cord injury, but different cNOS may play different roles.