Expression of NOS after phochemically induced focus cervical spinal cord ischemia in rats

    ZHOU Baiª²Yu, CHI Liª²Yi

    Department of Neurology, 451 Hospital of Chinese PLA, Xi¡¯an 710054, China

    ¡¾Abstract¡¿ AIM: To study the NOS expression after focal cervical spinal cord ischemia in rats. METHODS: Nintyª²five SD rats were divided into two large groups: control group (n=20) and experimental group (n=75). The latter was divided into three subgroups according to the time of irradiation and each subgroup was further divided into five small groups according to the time points of survival. The model of the cervical spinal cord ischemia was made by photochemical method, the behaviors of the rats by Menzies¡¯ method, the expression of NOS was observed by NADPHª²d histochemistry, and the histology of cervical spinal cord by counterstaining with neutral red. RESULTS: The focus injury and behavioral abnormity were not found in control group and the 5 minute group. In the 10 minute group, the score of nerve functional loss was moderate, the local pigmentation and a vast amount of NOSª²like positive neurons were found in the ventral motoneuron and intermediate zone, which were timeª²dependent: Appearing at the third day, peaking in the first week, reducing in the second week and disappearing in the third week. In the 15 minute group, the spinal cord sunk apparently and the score of nerve functional loss was severe, with only a few NOSª²like positive neurons, which was probably due to necrocytosis and neuron dropping. CONCLUSION: The photochemical method is satisfactory for the establishment of the model of focus cervical spinal cord ischemia in rats. Spinocervical spondylosis may be related to the NOS expression. ......