Effects Of Buchangnaoxintong Against Behavior And Pathology In Vascular Dementia Rats Induced By Chronic Cerebral Ischemia

With the arrival of aging coen, the incidence of dementia is increasing. InEurope and America, AD is the majority. While in Asia, VD is the most commontype. VD is an impairment of cognitive function of caused by cerebrovasculardisease. The research of VD is complicated. In the past, it is considered thatmost patients of VD are caused by cerebral infarction. Recently, chronic andcontinual decreasing of CBF begin to play an important role. Because VD issomewhat reversible, so we want to interfere it in the nonage of the infarction,and to examine the way of delay the progression of dementia. Recently, some researches raised that deep part of white matter had a closerelationship with VD. White matter is supported by the end of arteries whichhave little ramus anastomoticus, so when the pour pressure decreased, it is whitematter which be affected at first. And the damage of white matter might causethe decreasing of metabolism of homonymy cortex, the hypofunction of cortexresult in the progressive impairment of cognitive function. The change of myelinbasic protein (MBP) can indicate the functional status of nerve fiber. Buchangnaoxintong is made from milkvetch root, sanguisuge , angle wormand so on, traditional medicine presume that it can promote the blood circulation.There are essays validate that this Chinese patent medicine can increase cerebralblood flow (CBF), decrease cerebral vascular resistance (CVR) apparently, andalso can prolong the clotting time (CT), commonly used in the treatment ofischemic cerebrovascular disease, but if it also can prevent the progressiveimpairment of cognitive function is seldom reported. So we want to examine thevalue of this medicine in the prevention of VD according to the observe theinfluence of this medicine to the ethology, pathology and the change of MBP inthe white matter of the vascular dementia rats induced by chronic cerebralischemia.This study Choose healthy male Wistar rats of 3-5 monthes, divided theminto 3 groups randomly as control group, operated group and treated group, theVD rat models after chronic cerebral hypoperfusion are established bypermanent bilateral common carotid arteries occlusion and the treated group arelavaged with Buchangnaoxintong after the operation. Morris water mazeexperiment is adopted to test the rat's memory change of each group, the escapeincubation period expressed the rat's memory ability. Brain samples with HEstaining and Bielschowsky staining from different lobes and hippocampus areobserved with light microscopic methods. The changes of MBP by theimmunohistochemical methods are observed. The result and analysis arefollowed:1. Behavioral changes: We take the escape incubation period of MWM asthe evaluation target. Compared with control group, the treated group and theoperated group's escape incubation period is longer(P<0.01);compared with theoperated group, the treated group 's escape incubation period is shorter(P<0.01).Compared with other ischemic models, this memory dysfunction induced by theocclusion of bilateral carotid arteries is more chronic and more permanent andwe concluded from the results in Morris water maze tests that chronichypoperfusion could result in chronic and permanent cognitive impairment. Andwe also can draw the conclusion that Buchangnaoxintong can relieve the degreeof cognitive impairment.2. Pathological changes of neuron: In the control group, thedegeneration and detachment of neuron could be seen, so did the necrosis ofthe neurons and hypertrophic glia. We thought these pathological changes weredue to the chronic and steady reduction of CBF, but not by the acute cerebralischemia. But the ischemic changes of the treated group are relieved apparently.3. Pathological changes of white matter: From the result of Bielschowskystaining, we can see that the white matter of the control group is arrangedcompactly, and that of the operated group is raritas and collapse. The changesabove mentioned aggravate as time goes by. But the white matter of treatedgroup arranged tightly relatively. The result of MBP staining by theimmunohistochemical methods is: Compared with control group, the expressionof MBP in white matter of the operated group is lower(P<0.01);but comparedwith the operated group, the treated group's the expression of MBP in whitematter is higher (P<0.01). So we can draw the conclusion thatBuchangnaoxintong can relieve the ischemia damage of the white matter.In a word, the conclusions we can draw are followed: â‘  Permanent bilateralcommon carotid arteries occlusion to the rats can lead to ischemic damage of theneuron and nerve fiber. â‘¡ Permanent bilateral common carotid arteriesocclusion to the rats can lead to chronic and permanent cognitive impairment. â‘¢Buchangnaoxintong can relieve the ischemic damage of neuron and nerve fibercaused by chronic ischemia.â‘£ Buchangnaoxintong can relieve the cognitiveimpairment caused by chronic ischemia.