Fig. 2. (A ) Experiment 1: Histopathologic outcome in each animal of the four groups at 48 h after reperfusion. The symbols filled circle, filled triangle, open triangle , and filled diamond  represent animals in the no remote ischemic preconditioning (RIPC)/no dimethylthiourea (DMTU), RIPC/no DMTU, no RIPC/DMTU, and RIPC + DMTU groups, respectively. *P = 0.002 versus  no RIPC/no DMTU. (B ) Representative photomicrographs of lumbar spinal cord sections (L5) at 48 h after reperfusion. Sections from a rabbit rated as Tarlov score 0 in the no RIPC/no DMTU group showed severe neuronal damage, as evidenced by disappearance of most of normal motor neurons in anterior spinal cord and extensive vacuolation of gray matter. Ischemic neurons were identified by cytoplasmic eosinophils with loss of Nissl substance and by the presence of pyknotic homogenous nuclei. Section from a rabbit rated as Tarlov score 4 in the RIPC/no DMTU group showed numerous normal motor neurons in the same area. The sections from the rabbits rated as Tarlov score 0–1 in the no RIPC/DMTU and RIPC + DMTU groups also showed severe neuronal damage in the anterior spinal cord and extensive vacuolation of gray matter. (Hematoxylin and eosin staining, magnification 200×). No RIPC/no DMTU = animal that received sham pretreatment before 20 minutes spinal cord ischemia; RIPC/No DMTU = animal that received two cycles of occlusion/reperfusion of bilateral femoral arteries for 10-/10-min interval 30 min before spinal cord ischemia; No RIPC/DMTU = animal that received sham pretreatment and dimethylthiourea administration (1 hour before sham pretreatment) before 20 minutes spinal cord ischemia; RIPC + DMTU = animal that received RIPC and dimethylthiourea administration (1 hour before pretreatment) before 20 minutes spinal cord ischemia.