| 1 Objective According to the theory of TCM about the relation of blood and water, the knowledge of mordern medicine and mordern experimental method, the present study tried to investigate the pathological and physiological changes of traumatic brain edema in order to identify the pathogenesis, diagnosis and treatment of brain edema. In order to provide theoretical and experimental evidence for promoting blood flow and alleviating water retention to treat brain edema, TBI animal model was used to study the feature of microcirculation disturbance after TBI and its impact on cerebral blood flow, permeability of blood-brain barrier and brain edema. We also tried to investigate the protective effects of promoting blood flow and alleviating water retention on microcirculation and brain edema after TBI. In addition, through observing the change of MMP-2 and MMP-9 on basement membrane and AQP4 on foot process of astrocyte, the mechanism of microvessel injury and the protective mechanism of chinese medicine Naoshuning to microvessel were investigated. 2 Method 2.1 The model of TBI was established by bumpiness of free falling body according to Feeney's, all experimental rats were devided into pseudoperarion group, TBI group, Naoshuning group and mannitol group. In Naoshuning group, we successively poured into rats' stomache with Naoshuning for 3 days before operation. 1 hour after the last administration on the 4th day, TBI models were induced. Rats' weight and neurological function score were detected each day after opertion within one week. Rats in mannitol group were intravenous injected 20% mannitol after operation. 2.2 We observed the variance of permeability of BBB by the method of Evans blue fluorometry. Water content in brain tissue were also evaluated. 2.3 We observed and analyzed microvessel area density by the method of blood vessel histochemical stain and image analysis. We observed the structural and functional change of microvessels with light and eletron microscope. We also detected fibrinogen and D-dimer in order to observe the change of coagulation-fibrinolusis of the blood system. 2.4 Immunohistochemistry was used to observe the brain protein expression of MMP-2,MMP-9 and AQP4 in rats with TBI. 2.5 MRI was successivly used to observe the the change of signal intensity and volume of abnormal high signal region on T2WI after TBI. 3 Result 3.1 After TBI, the beam-walking ability of rats was seriously damaged and the weight of rats was lost obviously. 7 days after TBI, the beam-walking time of rats in TBI group was 16.46±3.27s, the rats' weight was lost 17.75±5.09g. The beam-walking time of rats in Naoshuning group (10.24±1.38s) significantly decreased compared with TBI group (P<0.01); The change of rats' weight (11.75±4.27g) was less compared with TBI group (P<0.05). Compared with TBI group, the beam-walking time of rats and the loss of rats' weight in mannitol group had no significantly difference (P>0.05). 3.2 6 hours after operation, water content of brain tissue (78.76±0.49%) and EB content (10.41±1.50μg/g) in the contusion side significantly increased in TBI group compared with pseudoperarion group (77.20±0.45%, 3.27±1.05μg/g) (P<0.01). They reached summit (79.63±0.45%, 11.76±2.22μg/g) 24 hours after operation and did not come back normal level 5 days after operation. 6h, 24h, 3d, 5d after operation, water content of brain tissue was respectively 78.14±0.37%, 78.93±0.47%, 78.23±0.63%, 77.70±0.33% in Naoshuning group. There was significant difference between Naoshuning group and TBI group (P<0.05 ). In mannitol group, water content of brain tissue was respectively 78.01±0.82%, 78.80±0.57%, 78.26±0.82%, 77.81±0.48%. There was significant difference between mannitol group and TBI group 6h, 24h and 3d after operation (P<0.05). There was no significant difference between Naoshuning group and mannitol group (P>0.05); In Naoshuning group, EB content in contusion brain tissue was respectively 8.50±1.33μg/g, 7.97±1.08μg/g, 6.57±1.93μg/g, 5.31±1.19μg/g. There was signi... |
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