| Objective:To confirm existence of cerebral-inflammatory reaction after brain-lymph-drainage block and then initially investigate its action mechanism by observing pathologic changes of brain tissue, expression levels of inflammatory factor tumour necrosis factor-alpha, (TNF-a)and interleukin-1 beta(IL-1β) and leucocyte infiltration in parietal cortex.Methods:Healthy-male Wistar rats(n=156) were randomly divided into Normal group (n=12), Operation-group (n=12) and Sham-operation group(n=12), and then every group was divided into six time points:12h,1d,3d,5d,7d and 14d. Rats in Normal group had not any treatment; Rats in Model group were separated and removed cervical superficial, deep and submandibular lymph nodes as well as afferent and efferent lymphatics. Rats in Sham-operation group were only separated but not remove cervical lymph nodes and deligate lymphatics. Obtaining different-time-point brain tissue and detecting the following indexes: Morphology changes of parietal cortex (HE staining), damage degrees of cortex neurons (Nissl's staining), neutrophil infiltration (myeloperoxidase techniques), changes of Leucocyte infiltration (CD45 labelling) and immune activities of TNF-a, IL-1βand intercellular adhesion molecule-1 (ICAM-1) in parietal cortex (immunohistochemistry).Results:1 Brain tissue showed rarefaction, leucocyte infiltration, Nissle-body staining light and content diminution at 1 day in Operation-group rats. Partial neurons became swelling and karyolysis and formed vacuoles in peri-neuron from 1 day, the above-mentioned changes significantly occurred at the 5th day. Nissle body staining deepened and its content increased, which restored to the normal level at 14th day after brain lymph drainage blockage. There were no markedly pathologic changes in the Normal and Sham-operation groups.2 MPO activities started to increased at 12h, reached the peak at the third day (compared with the Normal and Sham-operation groups,p＜0.01),decreased at the 5th day and restored at the 7th day in-cerebral cortex of operation-group rats; CD45 positive-staining cells started to increased at 12h, reached the peak at the 3th day (compared with the Normal and Sham-operation groups, p＜0.01), lasted to the 5th day and restored to the normal level at the 14th day. The above-mentioned indexes had no significantly changes in the Normal and Sham-operation groups.3 Expression levels of TNF-a, ICAM-1 and IL-1βincreased at 12h, reached the peak at the 3th day (compared with the Sham-operation groups,p＜0.01). Expression peak of IL-1βlasted to the 5th day, decreased at the 7th day and restored at the 14th day; Expression levels of TNF-a and ICAM-1 decreased at the 5th day and restored at the 7th day in cerebral cortex of Operation-group rats. TNF-a and IL-1βwere chiefly located in glia cells but ICAM-1 was located in blood vessel endothelial cells, which were stained in cytoplasm or cytomembrane. No expression of TNF-a but micro-expression of ICAM-1 and EL-1βwere observed in the Normal and Sham-operation groups.4 Correlation analysis:After brain-lymph-drainage blockade in rats, expression levels of the following indexes had similar change trends and strong-positive correlation:IL-1βand ICAM-1 (r=0.789;,p＜0.01), TNF-a and ICAM-1 (r=0.743;p＜0.05), CD45 positive cells and ICAM-1 (r=0.821;p＜0.01),MPO activities and ICAM-1(r=0.591;p＜0.01), CD45 positive cells and nissl staining(r=0.691;p＜0.05) and MPO activities and nissl staining (r=0.725;p＜0.05).Conclusion:1 Neuron occurred tumefaction and necrosis after brain lymph drainage block in rats.2 There existed expression of inflammation cytokine TNF-a, IL-1βand ICAM-1 and leucocyte infiltration in cerebral in rats brain lymph drainage block brain damage.3 There were markedly correlation between inflammation reaction factor and leucocyte infiltration.4 Brain tissue existed not only expression of inflammation cytokine but also leucocyte infiltration in rats after brain lymph drainage blockage, inflammation cytokine induced leucocyte infiltration by expression of ICAM-1, and both play an import part in brain damage pathologic process caused by brain lymph drainage blockage. |
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