(Department of Anesthesiology，Xijing Hospital，Fourth Military Medical University，Xi'an710033，China)

    Keywords:tetramethylpyrazine;spinal cord injuries;reper-fusion injury;dose-response relationship，drug;rabbits

    Abstract:AIM To investigate the dose-response relation between tetramethylpyrazine(TMP)，an intravenous drug made from traditional Chinese herbs，and the neurologic in-jury related to spinal cord ischemia and reperfusion in rab┐bits.METHODS Twenty-six male New Zealand white rab-bits were anesthetized with isoflurane and spinal cord is-chemia was induced for20min by infrarenal aortic occlusion.Animals were randomly allocated to four groups.Group C re-ceived no pharmacologic intervention.Group T1 ，Group T2 and Group T3 received15，30and60mg kg

    -1 TMP intra-venous infusion respectively within30min at the end of is-chemia.Neurologic status was scored by the Tarlov criteria(in which4is normal and0is paraplegia)at4，8，12，24，and48h after reperfusion.All the animals were sacrificed at48h after reperfusion and the spinal cords(L5 -L7 )were re-moved immediately for histopathologic study.RESULTS All the animals survived the experiment.The neurologic scores at each timepoint and the number of normal neurons in the anterior spinal cord48h after reperfusion of Groups T1 ......