Background:Paraplegia after spinal cord ischemia is a devastating condition in the clinic.Here,we develop an awake rabbit model of spinal cord ischemia with delayed paraplegia and explore the influence of ambient temp...Background:Paraplegia after spinal cord ischemia is a devastating condition in the clinic.Here,we develop an awake rabbit model of spinal cord ischemia with delayed paraplegia and explore the influence of ambient temperature on the outcomes after injury.Methods:A total of 47 male rabbits were involved in the present study.Transient spinal cord ischemia was induced by occluding the infrarenal abdominal aorta of awake rabbits at different ambient temperatures.To find the optimal conditions for developing delayed paraplegia,hindlimb motor function after ischemia was evaluated between experiments.Results:The onset and magnitude of ischemic injury varied with the ambient temperature maintained during the peri-i schemia period.More serious spinal cord injury occurred when ischemia was induced at higher temperatures.At 18°C,25-minute ischemia resulted in 74%of rabbits developing delayed paraplegia.At a temperature of 28°C or higher,most of the animals developed acute paraplegia immediately.While at 13°C,rabbits usually regained normal motor function without paraplegia.Conclusion:This awake rabbit model is highly reproducible and will be helpful in future studies of delayed paraplegia after spinal cord ischemia.The ambient temperature must be considered while using this model during investigation of therapeutic interventions.展开更多
Objective To clarify the pathologic change of the motor neuron on spinal cord ischemia reperfusion injury delayed paraplegia.Methods The infrarenal aorta of White New Zealand rabbits(n=24) was occluded for 26 minutes ...Objective To clarify the pathologic change of the motor neuron on spinal cord ischemia reperfusion injury delayed paraplegia.Methods The infrarenal aorta of White New Zealand rabbits(n=24) was occluded for 26 minutes using two bulldog clamps.Rabbits were killed after 8,24,72,or 168 hours(n=6 per group),respectively.The clamps was placed but never clamped in sham-operated rabbits(n=24).The lumbar segment of the spinal cord(L5 to L7) was used for morphological studies,including hematoxylin and eosin staining,the expression of bcl-2 and bax proteins in spinal cord was detected with immunohistochemistry.The apoptotic neurons in spinal cord were measured with terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end-labeling of DNA fragments(TUNEL) staining.Results Delayed paraplegia occurred in all rabbits of ischemia reperfusion group at 16-24 hours,but not in sham groups.Motor neurons were selectively lost at 7 days after transient ischemia.After ischemia,the positive expression of bcl-2 protein were in the sham controls but decreased significantly as compared with that of the IR group(P<0.01),especially in 72 hours reperfusion.The positive expression of bax protein were also in the sham controls, but increased in the IR group,especially in 72 hours reperfusion;In addition, TUNEL study demonstrated that no cells were positively labeled until 24 hours after ischemia,but nuclei of some motor neurons were positively labeled at peak after ischemia reperfusion at 72 hours.Conclusion Spinal cord ischemia in rabbits induces morphological and biochemical changes suggestive of apoptosis.These data raise the possibility that apoptosis contributes to neuronal cell death after spinal cord ischemia reperfusion.展开更多
基金supported by the Science and Technology Research Project(KJQN202212805)of the Chongqing Education Commissionthe Special Funding Project(2021XJS08)of Army Medical University。
文摘Background:Paraplegia after spinal cord ischemia is a devastating condition in the clinic.Here,we develop an awake rabbit model of spinal cord ischemia with delayed paraplegia and explore the influence of ambient temperature on the outcomes after injury.Methods:A total of 47 male rabbits were involved in the present study.Transient spinal cord ischemia was induced by occluding the infrarenal abdominal aorta of awake rabbits at different ambient temperatures.To find the optimal conditions for developing delayed paraplegia,hindlimb motor function after ischemia was evaluated between experiments.Results:The onset and magnitude of ischemic injury varied with the ambient temperature maintained during the peri-i schemia period.More serious spinal cord injury occurred when ischemia was induced at higher temperatures.At 18°C,25-minute ischemia resulted in 74%of rabbits developing delayed paraplegia.At a temperature of 28°C or higher,most of the animals developed acute paraplegia immediately.While at 13°C,rabbits usually regained normal motor function without paraplegia.Conclusion:This awake rabbit model is highly reproducible and will be helpful in future studies of delayed paraplegia after spinal cord ischemia.The ambient temperature must be considered while using this model during investigation of therapeutic interventions.
基金This study was supported by the Foundation of Science of Shaanxi Province Health Department(No.04012).
文摘Objective To clarify the pathologic change of the motor neuron on spinal cord ischemia reperfusion injury delayed paraplegia.Methods The infrarenal aorta of White New Zealand rabbits(n=24) was occluded for 26 minutes using two bulldog clamps.Rabbits were killed after 8,24,72,or 168 hours(n=6 per group),respectively.The clamps was placed but never clamped in sham-operated rabbits(n=24).The lumbar segment of the spinal cord(L5 to L7) was used for morphological studies,including hematoxylin and eosin staining,the expression of bcl-2 and bax proteins in spinal cord was detected with immunohistochemistry.The apoptotic neurons in spinal cord were measured with terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end-labeling of DNA fragments(TUNEL) staining.Results Delayed paraplegia occurred in all rabbits of ischemia reperfusion group at 16-24 hours,but not in sham groups.Motor neurons were selectively lost at 7 days after transient ischemia.After ischemia,the positive expression of bcl-2 protein were in the sham controls but decreased significantly as compared with that of the IR group(P<0.01),especially in 72 hours reperfusion.The positive expression of bax protein were also in the sham controls, but increased in the IR group,especially in 72 hours reperfusion;In addition, TUNEL study demonstrated that no cells were positively labeled until 24 hours after ischemia,but nuclei of some motor neurons were positively labeled at peak after ischemia reperfusion at 72 hours.Conclusion Spinal cord ischemia in rabbits induces morphological and biochemical changes suggestive of apoptosis.These data raise the possibility that apoptosis contributes to neuronal cell death after spinal cord ischemia reperfusion.
