| Objective: Vertebral artery injuries (VAI) were seen commonly in cervical part trauma and damage due to operation. After VAI, Clinic symptoms were confounded easily with the cerebral trauma, and they didn't have special manifestation in the ordinary screening. Accordingly, VAI often were diagnosed incorrectly. At present, researchers still haven't arrived at the final conclusion if VAI have obvious influence on the cervical spinal cord. But mortality rate is very high in patients with bilateral vertebral arteries injuries in clinical practice. Ninety percent of blood supply to the cervical spinal cord and spinal nerve root comes from bilateral vertebral arteries. So more and more researchers pay attention to VAI. In order to understand the effect on the blood supply to the cervical spinal cord after bilateral vertebral arteries were injuried, we made use of the animal model of complete block rabbits' bilateral vertebral arteries in the first portion to get observations of blood stream change of cervical spinal cord. We utilized the identical animal model to observe the change of the evoked potential in order to comprehend the relation between the bilateral vertebral arteries injuries and functional alteration of the cervical spinal cord. Methods: The animal model was based on block rabbits' bilateral vertebral arteries in the first portion by completely ligating them. The change of blood supply to cervical spinal cord was measured by the Laser Doppler Flowmetry after 4 hours, 8 hours, 24 hours, 7 days and 56 days when the operation was finished. The evoked potential was used to observe the functional alteration of cervical spinal cord in the same period. The cervical spinal cord tissue was processed with the hematoxylin and eosin stain and the electron microscope. Expressions of C-FOS, BCL-2 and NSE in the cervical spinal cord tissue were examined by the technology of immunohistochemistry.Results: 1. After 4 hours which rabbits' bilateral vertebral arteries were blocked up, the blood stream of the cervical spinal cord came down to the lowest level; After 8 hours, the blood stream began to get back gradually; After 24 hours and 7 days, the blood stream didn't recover the normal level (P<0.01); However, the blood stream of rabbits' cervical spinal cord reached the normal blood stream level (P>0.05) after 56 days. 2. After 4 hours, the evoked potential didn't show any change between the normal control rabbits and the operational rabbits (P>0.05); After 8 hours, the latent period and amplitude of the evoked potential showed some alteration, which kept the identical level after 24 hours; After 7 days, the latent period and amplitude of the evoked potential got back to the normal level (P>0.05); The latent period and amplitude of the evoked potential kept the same level between operational rabbits and normally controlled rabbits(P>0.05) after 56 days.3. Expressions of C-FOS and BCL-2 kept semblable change: After 4 hours, Expressions of C-FOS and BCL-2 were the strongest; after 8 hours, Expressions of C-FOS and BCL-2 in ischemic cervical spinal cord tissue were higher than that in normal cervical spinal cord tissue, but that were inferior to the former; After 24 hours, expressions of C-FOS and BCL-2 were gotten back to the normal level; And expressions of C-FOS and BCL-2 were showed no alteration after 7 days and 56 days. NSE was showed normal expression when operation was done after 4 hours; Expression of NSE was enhanced markedly after 8 hours; And expression of NSE was showed semblable alteration after 24 hours; But expression of NSE was showed no obvious alteration after 7 days and 56 days.Conclusion: When rabbits' bilateral vertebral arteries were blocked up completely in the first portion, the blood stream of cervical spinal cord showed descent transparently during a short term. By the compensation mechanism of blood supply, the blood supply to cervical spinal cord gradually recovered the normal level. During the blood stream changing, ischemic injuries in the cervical spinal cord tissue l...
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