ABSTRACT
Objective To observe the evolution of astrocytes,GDNF,BDNF and Jak-STAT signal pathway after spinal cord ischemia-reperfusion injury in rabbits.Methods Spinal cord ischemia was induced by means of balloon occlusion of the infrarenal aorta for 22 minutes in 54 male New Zealand white rabbits.We assigned rabbits to 9 groups (n =6),one sham group,eight operation groups.The operation process in the sham group was the same as the operation group except the ischemia reperfusion of the spinal cord.At 0 h,1 h,2 h,3 h,8 h,24 h,48 h and 72 h after reperfusion,animals were sarcrificed and the spinal cord was removed for histologic,immunohistochemical study and western blotting.Results Normal neurons were decreased with the extension of reperfusion time.Levels of GFAP increased at 3 h and reached a peak at 48 h after reperfusion.GDNF was increased reaching two peaks after injury,the first peak was at 3 h,the second was at 72 h.BDNF level was increased and peaked at 24 h after reperfusion.The expression of p-STAT3 showed a biphasic pattern which peaked at 1h and 48 h.GFAP,GDNF,BDNF were rare and the level of p-STAT3 could be neglected in sham group.Conclusion Spinal cord ischemia-reperfusion injury could induce the activation of astrocytes,the expression of GDNF,BDNF and the activation of JakSTAT signal pathway.They showed different expression rules in this study.
ABSTRACT
Objective: To observe the activation of microglia and the changing rule of inflammatory cytokine as IL-6, IL-10 and nuclear factor-κB (NF-κB) in experimental rabbits after spinal cord ischemia reperfusion (SCIR) injury in order to provide theoretical basis for post-conditioning time. Methods: Rabbit SCIR injury model was established by thoracic aorta balloon occlusion. 54 New Zealand male adult white rabbits were divided into 9 groups: Sham group (the animals received balloon implantation without occlusion), SCIR-0h group (reperfusion was conducted at 0 hour of spinal cord ischemia), SCIR-1h, -2h, -3h, -8h, -24h,-48h and -72h groups. n=6 in each group. The number of normal and apoptosis neurons, the levels of Iba-1, IL-6, IL-10 and NF-κB in spinal tissue were examined and compared among different groups respectively. Results: The number of normal neuron was decreasing with the extended reperfusion time, TUNEL-positive neuron began to increasing in SCIR-8h group and the peak was reached in SCIR-24h group. The expression of Iba-1 began to elevating in SCIR-2h group and the peak was obtained in SCIR-8h group; NF-κB began to rising in SCIR-3h group and the peak was observed in SCIR-8h group; both IL-6 and IL-10 arrived the peak in SCIR-24h group. The expressions of NF-κB, IL-6 and IL-10 were positively related to Iba-1 level. Conclusion: Microglia activation had dynamic changes in experimental SCIR rabbits and the expression levels of NF-κB, IL-6 and IL-10 were positively to microglia activation; post-conditioning time at front and back to microglia activation may reduce neuron injury.