| Objectives:To investigate the effect of curcumin on the expression of NF-κB and Hsp70 after spinal cord ischemic- reperfusion injury (SCII) in rats, we construct a model of SCII in order to approach the mechanism of action.There is no doubt that it will help us explore therapia target for SCII in molecular level,and provide new idea for treat spinal cord ischemic.Methods: 72 male SD rats were randomly divided into curcumine experimental group (n = 24),ischemic model group (n = 24)and control group (n = 24) . Chloral Hydrate 0.3mg/kg abdominal cavity anesthesia after,to lie it on the back,and unfolding abdominal.Cavity in sterility and exposure abdominal aorta, then to identify amb-renal arteries,meanwhile,we can occlusion abdominal aorta by means of untrauma bulldog clamp.A model of spinal cord ischemic-reperfusion injury was completed with intercepting rat's abdominal aorta between right and left renal artery for experimental group and model group, while there was nothing done in control group. Each rat had been administered 20mg/kg curcumin 10min before ischemia starts via sublingual vein in experimental group and NS in model group, respectively. Besides, an equal NS can be administered in control group. The expression of NF-κB and Hsp70 in myeloid tissue was analyzed for 6 rats at different intervals (3,12,24 and 72h) after ischemic- reperfusion injury by means of HE,immunohistochemical and Western blot methods.Results:1 The histology change of rat myeloid tissue1.1 HE staining In the normal control group:clear cell outline, distinct nucleoli , and homogeneous hyperchromatic cytoplasm is observed . The whole tissue was intact and clear-cut. In the ischemia model group: 3h after reperfusion, the cellular was swelling, and the nucleoli became indistinct. The cell outline was indistinct, the nucleus was shrunken and the cytoplasm was of vacuolate degeneration at 12h. At 24h, most neurons in the gray matter showed the extensive necrosis, and a great deal of vacuolation was observed in the cytoplasm. At 72h, chaos in the structure of the gray matter, the proliferation of gliocytes, hemorrhage focus can be observed. In the Curcumin experimental group: 3h after reperfusion, clear cell outline, distinct nucleoli , lightly edematous tissue can be observed . 12h after reperfusion, lightly swelling cellular, indistinct nucleoli in partial neurons is observed. The pathological changes were better than the ischemia group from 24h to 72h. Tissue swelling was lightened. Degeneration and vacuolation was observed in certain neurons in gray matter .1.2 The expression of NF -κB p65 by ImmunohistochemistryThere were expressions in NF-κB and p65 in all groups. The expression of NF -κB and p65 in model group increased at 3h after reperfusion, peaked at 24 h(P<0.01), and reduced at 72 h.While in the curcumin experimental group the expression of NF -κB p65 was moderately increased at the same points of time( P<0.05), higher than that of the normal control group.1.3 The expression of Hsp70 by Immunohistochemistry: There are expressions of Hsp70 in spinal cord of each group. 3h after reperfusion, the model group began to increase its expression, and it significantly increased and reached its peak (P <0.05) at 24h after reperfusion. Hsp70 expression in the experimental group of curcumin was moderately increased (P <0.05) at the same point of time, but still higher than that of the control group.2 The expressions of NF-κB and hsp70 by Western blotIn the curcumin, Experimental group and model group ,the expressions of NF-κB and Hsp70 protein in the rats'spinal cord tissue after ischemia-reperfusion showed similar tend at the same point of time. 3h after reperfusion, NF-κB and Hsp70 protein in the experimental group began to increase (P <0.05 compared with the control group NC), and the protein expression correspondingly increased in a time-dependent manner. It significantly increased (P <0.01) at 12h, reached its peak (P <0.05) at 24h, and gradually reduced at 72h. The control group only showed a weak NF-κB and Hsp70 protein expression.3 The results indicated that as the spinal cord histopathology showed:Neural cell damage in experimental group of curcumin is relatively lighter, compared with the model group. In the experimental group, the expression of NF-κB was relatively low after perfusion injury at the same point of time while the expression of Hsp70 was relatively high. The differences were of statistically significance (P <0.05), indicating that curcumin pretreatment can exert a protective effect on rat spinal cord Ischemia-reperfusion injury. It also found that the expression of NF-κB and Hsp70 gradually increased after ischemia and reperfusion in a time-dependent manner, and peaked at 24h.Conclusion:1. Spinal cord ischemia-reperfusion injury model is an ideal animal model in clinically ,which is similar to human being of ischemia-reperfusion injury.2. Spinal cord ischemia-reperfusion injury can induce a series of inflammatory changes in the organization. And increasing the expression of NF-KB and Hsp70 may play an important protective role in face of the stress on spinal cord.3. Curcumin could inhibit the early inflammatory response after spinal cord ischemia-reperfusion injury, and it takes a protective effect on spinal cord ischemia-reperfusion injury, while regulating of the expression of Hsp70 may be one of the mechanisms. |
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