| The preliminary experimental study showed that, New QINGKAILING plays a vital role on the treatment of cerebral ischaemic cascade. New QINGKAILING can obstruct the neural toxicity of excitatory amino acids, the production of free radical, the cell apoptosis and the inflammation casasde and improve the function of endothelial cells and neuron. All the development provide evidence for the further study of New QINGKAILING's protection to the blood-brain barrier (BBB) post cerebral ischaemia. This paper includes two parts: documental research and experimental research. The documental research includes two parts: fundamental research of mechanism of BBB damage post cerebral ischaemia, traditional Chinese medicine aimed to the treatment of BBB damage post cerebral ischaemia. The study used the model of rat middle cerebral artery occlusion (MCAO). It observed the injury of BBB basement membrane (BM) post cerebral ischaemia and the protection of New QINGKAILING to it. It also analysed the relationship between the integrity of BM, the permeability of BBB and the damage of neuron. The study may give some evidence that New QINGKAILING protects neoruns through reducing BBB injury. The results are as following: 1 Pathology obserbation Through hematoxylin and eosin staining, it can be seen that the brain structure of normal group is integrated. While 2h to 72h after MCAO, neurons of the cortex of model group manifested evident loss and the density of them decreased. The condensed cytoplasmic of neurons showed red dyeing and nuclei of neurons showed Shrinkage. The proliferation and edema of glia cell were evident. Interstitial around the vascular became rarefied with inflammatory cell assembled in it, the leukocyte adhered to endothelial cells and impacted within the vascular. Scattered lymphocyte could be seen in ischemic brain tissue. Neurons of ischemic contralateral cortex show normal characters. The treatment group had the varying improvement on pathological changes respectively. The nerve cell swelling, karyopyknosis, the spongiocyte proliferation swelling, the blood pioe wall twists, pathological change and so on accumulation has the change for the better, the neutral granular cell and the lymphocyte infiltrate the reduction. 2 The exprssion of components of BM and matrix matelloproteinases (MMPs) varied as the cerebral ischaemia goes on. The expression of three components began to reduce 2h after MCAO, and increased from 24h to 72h with deferent levels. There were different between the penumbra and the center of ischaemia. Collagon IV (CoIV) began to decrease 2h after MCAO, reached the lowest at 12h. It began to increase 24h after MCAO, was lower than normal level until 72h. Another component fibronectin (FN) also decrease 2h after MCAO, reached the lowest at 12h, and began to increase 24h, but it was higher than normal from 48h to 72h. The third component laminin (LN) didn't decrease from 2h to 24h, but went higher than normal from 48h to 72h. The expression of MMP-9 began to increase 2h after MCAO, reached the peak at 48h, and persisted to 72h. Its expression of the penumbra was higher than the center. The expression of MMP-2 was at a low level 2h after MCAO, it didn't increase markedly until 48h to 72h. Its expression of the penumbra was also higher than the center. 3 The relationship between the permeability of BBB and the damage of neuron post ischaemia The endogenous immunoglobulin G (IgG) leaked off 6h after MCAO, persisted to 72h, with larger area and quantity. The neuron specificity enolase(NSE) can leak off from the neuron after MCAO. It causes the content of NSE in the blood and cerebrospinal fluid rising. The content of NSE increased 6h after MCAO in the serum,and persisted rising as time went on. The infarct volume began to increase 6h after MCAO, and reached the peak at 72h. 4 The influnce of New QINGKAILING on BM post ischaemia New QINGKAILING can block the degradation of BM at the very beginning of ischaemia, and accelerate repairing of it. Compared to the model group, New QINGKAI... |
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