Study On The Preliminary Mechanism Of Prevention And Treatment Of Vascular Dementia Based On Neurovascular Depressive Pathogenesis And Antelope Gouteng Decoction

Experiment1A rat model of vascular dementia funder hypercholesterolemiaObject:To develop a new model of vascular dementia for evaluating TCM prescriptions.Methods:Eighty-eight male Wistar rats were randomly divided into4groups. At d00, d42, d70, d98(ni=20,20,24,24) during fatty-feeding, rats in each group did further into10or12subgroups (ni=2), respectively. Lacunar strokes were replicated with the injection of thrombi which coagulated artificially from itself blood. The median lethal doses were regressed from acumulative mortality in each geometric thrombus doses (k=0.75,0.5,0.85,0.85), respectively. The degree of vascular dementia was evaluated as exploratory, learning and memorizing abilities. The median effective dose of thrombus for replicating rat model was regressed from dementia scores which were derived from the abilities. The linear correlation was regressed between the values of LD50or ED50and the durations (days) of hypercholesterolemia. This model of vascular dementia was pathologically confirmed as the neural injuries from lacunar stroke in rats.Results:The hypercholesterolemia was indicated as elevated TC, TG, LDL-c, and decreased HDL-c. The values of LD50with its IC95were1525.0(1361.0-1709.0),584.3(490.1-696.6),168.7(163.7-173.8), or62.4(59.5-65.4) mg/ml, at d00, d42, d70, and d98, respectively. There is a linear regression between the values of LD50and the durations of hypercholesterolemia (y=-15.33x+1390.0, R=0.963, P<0.05). The values of ED50with its IC95were528.8(340.5-821.4),217.0(20.84-2259.0),96.3(23.4-402.6), or47.0(43.7-50.6) mg/ml from dementia score, at doo, d42, d70, and d98, respectively. There is a linear regression between the values of ED50and the durations of hypercholesterolemia (y=-4.992x+484.2, R=0.965, P<0.05). The neural injuries were demonstrated as neural degeneration and necrosis.Conclusions:For evaluating TCM, a model of vascular dementia in rats is set up with the lacunar stroke from self thrombosis during hypercholesterolemia. This model from lacunar stroke is useful to investigate the pathogenesis and treatment of vascular dementia.Experiment2The stability for replicating a rat model of vascular dementia with syndrome of phlegm and blood stasis Object:To explore the stability for replicating a rat model of vascular dementia with syndrome of phlegm and blood stasis.Methods:Sixty male Wistar rats were divided into5groups by weight and lipids. Rats fed with normal diet and injected with NS as shame, the others fed with high-fat diet and injected microthrombi(150.0mg/ml)1.31ml/Kg at d70, SLT(33.3mg/Kg) was used to prevent and cure vascular dementia at d-3. Exploring ability was detected by Open-field test at d78, learning and memory ability were detected by Morris maze test at d79. All rats were sacrificed for pathological examination at d84, the edema of microvascular and neuron, the number of nissl bodies in cortex and neurons in hippocampal CA1region was counted with morphometry.Results:Compared with the sham group, the ability of the exploring, learning, memory in model (P<0.01) decreased33.24%,48.75%,30.29%, respectively. The edema of microvascular and neuron increased64.5,20.6times, respectively. The number of nissl bodies and neurons was increased69.00%and28.55%. In SLT (P<0.01) group, the ability of the exploring, learning, memory increased0.30,0.38,0.40times, respectively. The edema of microvascular and neuron decreased32.15%and30.61%. The number of nissl bodies and neurons was increased1.58and0.18times. Compared with model group, the ability of the exploring, learning, memory in ISO (P<0.01) decreased14.32%,21.36%,12.36%times, respectively; the edema of microvascular and neuron increased0.24and0.33times; the number of nissl bodies and neurons was decreased11.54%and13.39%.Conclusion:The rat model of vascular dementia with syndrome of phlegm and blood stasis can be replicated with fat diet, ISO and microthrombi. But the high mortality resists the replication of the vascular dementia model.Experiment3Effective comparing of prescriptions for vascular dementia in ratsObject:To evaluating the effective prescriptions that prevent and cure vascular dementia.Methods:Sixty male Wistar rats were divided into5groups by weight and lipids. Rats fed with normal diet and injected with NS as shame, the others fed with high-fat diet and injected microthrombi(150.0mg/ml)1.31ml/Kg at d70, SLT(33.3mg/Kg), SLT(10.0g/Kg), LYGTY(8.1g/Kg), was used to prevent and cure vascular dementia at d-3. Exploring ability was detected by Open-field test at d78, learning and memory ability were detected by Morris maze test at d79. All rats were sacrificed for pathological examination at d84, the edema of microvascular and neuron, the number of nissl bodies in cortex and neurons in hippocampal CA1region was counted with morphometry.Results:Compared with the sham group, the ability of the exploring, learning, memory in model (P<0.01) decreased33.24%,48.75%,30.29%, respectively. The edema of microvascular and neuron increased64.5,20.6times, respectively. The number of nissl bodies and neurons was increased69.00%and28.55%. In SLT (P<0.01), KXS (P<0.01), LYGTY (P<0.01) groups, the ability of the exploring, learning, memory increased (0.30,0.38,0.40),(0.48,0.18,0.20)、(0.43,0.67,0.78)times, respectively compared with the model group; the edema of microvascular and neuron decreased (32.15%,15.78%,54.18%),(30.61%,13.54%,48.36%), respectively; the number of nissl bodies and neurons was increased (0.30,0.23,0.63) and (0.18,0.12,0.26) times, respectively.Conlusion:SLT, KXS and LYGTY can prevent and cure vascular dementia effectively and LYGTY has the best potency.Experiment4Pharmacological mechanisms of LYGTY on vascular dementia in rats from neurovascular couplingObject:To study the pharmacological mechanisms of LYGTY on vascular dementia from neurovascular coupling.Methods:Seventy-two male Wistar rats were divided into5groups by weight and lipids. Rats fed with normal diet and injected with NS as shame, the others fed with high-fat diet and injected microthrombi(150.0mg/ml)1.31ml/Kg at d70, pentoxifyllinum(68.9mg/Kg), LYGTY(2.6,8.1,25.6g/Kg), was used to prevent and cure vascular dementia at d.3. Exploring ability was detected by Open-field test at d78, learning and memory ability were detected by Morris maze test at d79. At d84:two cranial window of6×4mm or diameter=2mm was opened over the right hemisphere and the dura was carefully removed. Neuron was excited by penicillin which induced epilepsy. The velocity of arteriole and EEG in cortex were recorded synchronously to calculate the ratio Δvelocity/ΔqEEG. All rats were sacrificed for pathological examination at d84, the edema of microvascular and neuron, the number of nissl bodies in cortex and neurons in hippocampal CA1region was counted with morphometry. The expressions of SOD3, NOX2, COX-1, COX-2, CYP4A, nNOS, iNOS, eNOS in cortex was detected by immunohistochemistry, western blot and RT-PCR.Results:Compared with the sham group, the ability of the exploring, learning, memory in model (P<0.01) decreased60.62%,60.62%,27.90%, respectively. The ability of NVC decreased73.83%. The edema of micro vascular and neuron increased67.5,26.6times, respectively. The number of nissl bodies and neurons was increased55.18%and46.73%. In pentoxifyllinum (P<0.01), LYGTY(Low,Middle,High)(P<0.01) groups, the ability of the exploring, learning, memory increased (0.32,0.28,0.35,0.35),(0.32,0.28,0.35,0.36),(0.33,0.26,0.29,0.38) times, respectively compared with the model group; the ability of NVC increased1.36、0.88、1.39、1.80times, respectively; the edema of microvascular and neuron decreased (71.53%,60.58%,72.63%,76.28%),(51.26%,36.82%,56.32%,75.81%), respectively; the number of nissl bodies and neurons was increased (0.83,0.34,0.87,0.89) and (0.38、0.29、0.37、0.74) times, respectively. The expressions of SOD3,nNOS, eNOS increased and the expressions of NOX2, COX-1, COX-2, CYP4A, iNOS decreased apparently in LYGTY groups.Conclusion:LYGTY can prevent and cure vascular dementia by protecting neurovascular coupling.