Effects of thyroid hormone on NF-κB and TNF-α in cerebra cortex of rats with bran ischemic reperfusion injury / 中华行为医学与脑科学杂志

ABSTRACT

Objective To investigate the effect of thyroid hormone on the expression of NF-κB and TNF-oα in the ischemic cortex of rats after focal cerebral ischemia-reperfusion.Methods 96 male SD rats were randomly divided into sham-operation group,sham-operation+T3 group,IR group and IR+T3 group.Using suture legal method to establish a rat model of middle cerebral artery occlusion for 2 h followed by reperfusion.In sham-operation+T3 group and IR+T3 group,T3 was given 3 days before ischemia and 1 hour after ischemia,respectively,intraperitoneal injection T3 10 μg/100 g for rats.Rats in other groups were given the same volume normal saline at the same time.The infarct size was determined by TTC staining at 24 h after reperfusion.HE staining was used to observe the morphological and structural changes of brain tissue.Using Real-time PCR method and immunohistochemical staining method to detect the expression of NF-κB mRNA,TNF-α mRNA and protein in ischemic cortex of rats.Results Compared with sham-operation group and sham-operation+T3 group,the pathological damage of brain tissue in IR group was obvious,while the pathologic damage of IR +T3 group was less than that in IR group.Immunohistochemistry assay showed that the expression of NF-κB was(49.19±5.55)in sham-operation group,(45.75±2.12) in sham-operation+T3 group,(56.88±2.23)in IR group and(50.25±1.67)in IR +T3 group,the expression of TNF-α was (22.50±3.07) in sham-operation group,(24.13±2.03) in sham-operation+T3 group,(37.25±2.82) in IR group and (30.25±1.67) in IR +T3 group,and the NF-κB,TNF-α in IR group were obviously higher than that in sham-operation group and sham-operation+T3 group(P＜0.05),while IR+T3 group were lower than that in IR group(P＜0.05).Real-time PCR showed that NF-κB mRNA,TNF-α mRNA level in IR group was the highest,which was higher than that of sham-operation group and sham-operation+T3 group(P＜0.05),and the NF-κB mRNA,TNF-oα mRNA expression in IR+T3 group were significantly decreased compared with that in IR group(P＜0.05).Conclusion Thyroid hormone has a protective effect on cerebral ischenia reperfusion injury,which may be achieved by reducing the expression of inflammatory factor NF-κB and TNF-oα.