Regional dynamic cerebral autoregulation across anterior and posterior circulatory territories:A detailed exploration and its clinical implications

Cerebral autoregulation(CA)is the mechanism that maintains stable cerebral blood flow(CBF)despite fluctuations in systemic blood pressure,crucial for brain homeostasis.Recent evidence highlights distinct regional variations in CA between the anterior(carotid)and posterior(vertebrobasilar)circulations.Noninvasive neuromonitoring techniques,such as transcranial Doppler,transfer function analysis,and near-infrared spectroscopy,facilitate the dynamic assessment of CBF and autoregulation.Studies indicate a robust autoregulatory capacity in the anterior circulation,characterized by rapid adjustments in vascular resistance.On the contrary,the posterior circulation,mainly supplied by the vertebral arteries,may have a lower autoregulatory capacity.in acute brain injuries such as intracerebral and subarachnoid hemorrhage,and traumatic brain injuries,dynamic CA can be significantly altered in the posterior circulation.Proposed physiological mechanisms of impaired CA in the posterior circulation include:(1)Decreased sympathetic innervation of the vasculature impairing compensatory vasoreactivity;(2)Endothelial dysfunction;(3)Increased cerebral metabolic rate of oxygen consumption within the visual cortex causing CBFmetabolism(i.e.,neurovascular)uncoupling;and(4)Impaired blood-brain barrier integrity leading to impaired astrocytic mediated release of vasoactive substances(e.g.nitric oxide,potassium,and calcium ions).Furthermore,more research is needed on the effects of collateral circulation,as well as the circle of Willis variants,such as the fetal-type posterior cerebral artery,on dynamic CA.Improving our understanding of these mechanisms is crucial to improving the diagnosis,prognosis,and management of various cerebrovascular disorders.

Characterization of astrocytes and microglial cells in the hippocampal CA1 region after transient focal cerebral ischemia in rats treated with Ilexonin A

Ilexonin A is a compound isolated from the root of Ilex pubescens,a traditional Chinese medicine.Ilexonin A has been shown to play a neuroprotective role by regulating the activation of astrocytes and microglia in the peri-infarct area after ischemia.However,the effects of ilexonin A on astrocytes and microglia in the infarct-free region of the hippocampal CA1 region remain unclear.Focal cerebral ischemia models were established by 2-hour occlusion of the middle cerebral artery in rats.Ilexonin A(20,40 or 80 mg/kg)was administered immediately after ischemia/reperfusion.The astrocyte marker glial fibrillary acidic protein,microglia marker Iba-1,neural stem cell marker nestin and inflammation markers were detected by immunohistochemistry and western blot assay.Expression levels of tumor necrosis factor-αand interleukin 1βwere determined by enzyme linked immunosorbent assay in the hippocampal CA1 tissue.Astrocytes were activated immediately in progressively increasing numbers from 1,3,to 7 days post-ischemia/reperfusion.The number of activated astrocytes further increased in the hippocampal CA1 region after treatment with ilexonin A.Microglial cells remained quiescent after ischemia/reperfusion,but became activated after treatment with ilexonin A.Ilexonin A enhanced nestin expression and reduced the expression of tumor necrosis factor-αand interleukin 1βin the hippocampus post-ischemia/reperfusion.The results of the present study suggest that ilexonin A has a neuroprotective effect in the hippocampus after ischemia/reperfusion,probably through regulating astrocytes and microglia activation,promoting neuronal stem cell proliferation and reducing the levels of pro-inflammatory factors.This study was approved by the Animal Ethics Committee of the Fujian Medical University Union Hospital,China.

Effect of electroacupuncture on glial fibrillary acidic protein and nerve growth factor in the hippocampus of rats with hyperlipidemia and middle cerebral artery thrombus

Electroacupuncture(EA)has been shown to reduce blood lipid level and improve cerebral ischemia in rats with hyperlipemia complicated by cerebral ischemia.However,there are few studies on the results and mechanism of the effect of EA in reducing blood lipid level or promoting neural repair after stroke in hyperlipidemic subjects.In this study,EA was applied to a rat model of hyperlipidemia and middle cerebral artery thrombosis and the condition of neurons and astrocytes after hippocampal injury was assessed.Except for the normal group,rats in other groups were fed a high-fat diet throughout the whole experiment.Hyperlipidemia models were established in rats fed a high-fat diet for 6 weeks.Middle cerebral artery thrombus models were induced by pasting 50%FeCl3 filter paper on the left middle cerebral artery for 20 minutes on day 50 as the model group.EA1 group rats received EA at bilateral ST40(Fenglong)for 7 days before the thrombosis.Rats in the EA1 and EA2 groups received EA at GV20(Baihui)and bilateral ST40 for 14 days after model establishment.Neuronal health was assessed by hematoxylin-eosin staining in the brain.Hyperlipidemia was assessed by biochemical methods that measured total cholesterol,triglyceride,low-density lipoprotein and high-density lipoprotein in blood sera.Behavioral analysis was used to confirm the establishment of the model.Immunohistochemical methods were used to detect the expression of glial fibrillary acidic protein and nerve growth factor in the hippocampal CA1 region.The results demonstrated that,compared with the model group,blood lipid levels significantly decreased,glial fibrillary acidic protein immunoreactivity was significantly weakened and nerve growth factor immunoreactivity was significantly enhanced in the EA1 and EA2 groups.The repair effect was superior in the EA1 group than in the EA2 group.These findings confirm that EA can reduce blood lipid,inhibit glial fibrillary acidic protein expression and promote nerve growth factor expression in the hippocampal CA1 region after hyperlipidemia and middle cerebral artery thrombosis.All experimental procedures and protocols were approved by the Animal Use and Management Committee of Beijing University of Chinese Medicine,China(approval No.BUCM-3-2018022802-1002)on April 12,2018.

Changes in secretory pathway Ca^(2+)-ATPase 2 following focal cerebral ischemia/reperfusion injury

This study aimed to investigate changes in secretory pathway Ca2＋-ATPase 2 expression following cerebral ischemia/reperfusion injury, and to define the role of Ca2＋-ATPases in oxidative stress. A rat model of cerebral ischemia/reperfusion injury was established using the unilateral middle cerebral artery occlusion method. Immunohistochemistry and reverse transcription-PCR assay results showed that compared with the control group, the expression of secretory pathway Ca2＋-ATPase 2 protein and mRNA in the cerebral cortex and hippocampus of male rats did not significantly change during the ischemic period. However, secretory pathway Ca2＋-ATPase 2 protein and mRNA expression reduced gradually at 1, 3, and 24 hours during the reperfusion period. Our experimental findings indicate that levels of secretory pathway Ca2＋-ATPase 2 protein and mRNA expression in brain tissue change in response to cerebral ischemia/reperfusion injury.

Flavonoids from Scutellaria baicalensis Georgi are effective to treat cerebral ischemia/reperfusion

Based on previous studies that have shown flavonoids from the stems and leaves of Scutellaria baicalensis Georgi are neuroprotective agents in a naturally senile, D-galactose, aging in vivo model, as well as an in vitro model of oxidative/hypoxic injury, we established a cerebral ischemia/reperfusion model in rats by middle cerebral artery occlusion. The light/electron microscopic observations found significant neuropathological changes including neuron loss or swelling and rough endoplasmic reticulum injury. Moreover, the activities of lactate dehydrogenase Na＋-K＋-ATPase, Ca2＋-ATPase and superoxide dismutase were significantly lowered, and the levels of malonaldehyde increased. In addition, the memory of rats worsened. However, treatment with flavonoids from Scutellaria baicalensis Georgi （35, 70 and 140 mg/kg） for 13 days dramatically improved the above abnormal changes. These results suggest that the ability of flavonoids from Scutellaria baicalensis Georgi in attenuating cerebral functional and morphological consequences after cerebral ischemia/reperfusion may be beneficial for the treatment of ischemic brain disease.

Effects of anisodamine on altered [Ca^(2+)]i and cerebral cortex ultrastructure following acute cerebral ischemia/reperfusion injury in rabbits

BACKGROUND： Calcium ion （Ca^2＋） overload plays an important role in cerebral ischemia/reperfusion injury. Anisodamine, a type of alkaloid, can protect the myocardium from ischemia and reperfusion injury by inhibiting intracellular calcium [Ca^2＋]i overload. OBJECTIVE： To investigate effects of anisodamine on [Ca^2＋]i concentration and cortex ultrastructure following acute cerebral ischemia/reperfusion in rabbits. DESIGN, TIME AND SETTING： Randomized and controlled trial was performed at the Department of Emergency, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology from September to December 2006. MATERIALS： Forty healthy rabbits were used to establish models of acute cerebral ischemia/reperfusion. Anisodamine was provided by Lianyungang Dongfeng Pharmaceutical Factory; Fura-2 was purchased from Nanjing Jiancheng Bioengineering Institute; dual-wave length fluorescent spectrophotometry system and DM-300 software were provided by Bio-Rad, USA; OPTON-EM10C transmission electron microscope was product of Siemens, Germany. METHODS： Forty rabbits were randomly divided into the following groups： sham operation, ischemia, ischemia/reperfusion, and anisodamine, with ten rabbits in each group. Models of complete cerebral ischemia injury were established. In addition, blood was collected from the femoral artery of rats in the ischemia/reperfusion and anisodamine groups to induce hypotension and establish repeffusion injury models. The bilateral common carotid artery clamp was removed from the anisodamine group 20 minutes after ischemia, and anisodamine （10 mg/kg body mass） was injected via the femoral vein. Rabbits in the sham operation group underwent only venous cannulation. MAIN OUTCOME MEASURES： [Ca^2＋]i concentration was determined using a dual-wave length fluorescent spectrophotometry system, and cortical ultrastructure was observed following uranyl-lead citrate staining. RESULTS： The levels of [Ca^2＋]i in the ischemia and ischemia/reperfusion groups were significantly increased, compared with the sham operation group （P 〈 0.01）, and the levels of [Ca^2＋]i in the anisodamine group were remarkably less than the ischemia and ischemia/reperfusion groups （P 〈 0.01）. Ultrastructural damage to the cortex was greatly aggravated with increasing levels of [Ca^2＋]i. In the ischemia group, cortical neuronal membranes were fragmentally damaged, including the mitochoudria and endoplasmic reticulum, as well as neufite swelling, and slight chromatin margination. In the ischemia/reperfusion group, the cellular membrane was ruptured with aggravated mitochondrial swelling, increased chromatin margination, obscure neufite structure, and the disappearance of endoplasmic reticulum. However, in the anisodamine group, cellular damage was obviously alleviated. The appearance and structure of cortical neurons was relatively normal, with intact cells. There was slight swelling of the mitochondria and endoplasmic reticulum, as well as mild chromatin margination. CONCLUSION： Cerebral tissue injury was related to increased [Ca^2＋]i levels following ischemia/ reperfusion. Anisodamine exhibited a protective role on acute cerebral ischemia/reperfusion injury by inhibiting the increase in [Ca^2＋]i levels.

Fluoxetine ameliorates cognitive impairments induced by chronic cerebral hypoperfusion via down-regulation of HCN2 surface expression in the hippocampal CA1 area

Aim To investigate whether tluoxetine, a selective serotonin reuptake inhibitor（ SSRI） , could amelio- rate cognitive impairments induced by chronic cerebral hypopeffusion in rats and to clarify the underlying mecha- nisms of its efficacy. Methods Rats were subjected to permanent bilateral occlusion of the common carotid arteries （two-vessel occlusion, 2VO）. Two weeks later, rats were treated with 30 mg · kg^-1 fluoxetine （intragastric injec- tion, i. g. ） for 6 weeks. Cognitive function was evaluated by Morris water maze （MWM） and novel objects recog- nition （NOR） test. Long-term potentiation （LTP） was used to address the underlying synaptic mechanisms. West- ern blot was used to quantify the protein levels. Results Fluoxetine treatment significantly improved the cognitive 2VO impairments caused by 2VO, accompanied with a reversion of 2VO-induced inhibitory of LTP. Furthermore, caused an up-regulation of hyperpolarization-activated cyclic nueleotide-gated channel 2 （HCN2） surface expres- sions in the hippocampal CA1 area and fluoxetine also effectively recovered the up-regulation of HCN2 surface ex- pressions. Conclusion Fluoxetine can ameliorate cognitive impairments induced by chronic cerebral hypopeffusion and a possible mechanism may via down-regulating HCN2 surface expression in the Hippocampal CA1 area.

Intercellular adhesion molecule-1 expression in the hippocampal CA1 region of hyperlipidemic rats with chronic cerebral ischemia

Chronic cerebral ischemia is a pathological process in many cerebrovascular diseases and it is induced by long-term hypedipidemia, hypertension and diabetes mellitus. After being fed a high-fat diet for 4 weeks, rats were subjected to permanent occlusion of bilateral common carotid arteries to establish rat models of chronic cerebral ischemia with hypedipiclemia. Intercellular adhesion molecule-1 expression in rat hippocampal CA1 region was determined to better understand the mechanism underlying the effects of hypedipidemia on chronic cerebral ischemia. Water maze test results showed that the cognitive function of rats with hyperlipidemia or chronic cerebral ischemia, particulady in rats with hypedipidemia combined with chronic cerebral ischemia, gradually decreased between 1 and 4 months after occlusion of the bilateral common carotid arteries. This correlated with pathological changes in the hippocampal CA1 region as detected by hematoxylin-eosin staining. Immunohistochemical staining showed that intercellular adhesion molecule-1 expression in the hippocampal CA1 region was noticeably increased in rats with hyperlipidemia or chronic cerebral ischemia, in particular in rats with hyperlipidemia combined with chronic cerebral ischemia. These findings suggest that hyperlipidemia aggravates chronic cerebral ischemia-induced neurological damage and cognitive impairment in the rat hippocampal CA1 region which may be mediated, at least in part, by up-regulated expression of intercellular adhesion molecule-l.

Delayed hippocampal neuronal death in young gerbil following transient global cerebral ischemia is related to higher and longer-term expression of p63 in the ischemic hippocampus

The tumor suppressor p63 is one of p53 family members and plays a vital role as a regulator of neuronal apoptosis in the development of the nervous system. However, the role of p63 in mature neuronal death has not been addressed yet. In this study, we first compared ischemia-induced effects on p63 expression in the hippocampal regions （CA1-3） between the young and adult gerbils subjected to 5 minutes of transient global cerebral ischemia. Neuronal death in the hippocampal CA1 region of young gerbils was significantly slow compared with that in the adult gerbils after transient global cerebral ischemia, p63 immunoreactivity in the hippocampal CA1 pyramidal neurons in the sham-operated young group was significantly low compared with that in the sham-operated adult group, p63 immunoreactivity was apparently changed in ischemic hippocampal CA1 pyramidal neurons in both ischemia-operated young and adult groups. In the ischemia-operated adult groups, p63 immunoreactivity in the hippocampal CA1 pyramidal neurons was significantly decreased at 4 days post-ischemia; however, p63 immunoreactivity in the ischemia-operated young group was significantly higher than that in the ischemia-operated adult group. At 7 days post-ischemia, p63 immunoreactivity was decreased in the hippocampal CA1 pyramidal neurons in both ischemia-operated young and adult groups. Change patterns of p63 level in the hippocampal CA1 region of adult and young gerbils after ischemic damage were similar to those observed in the immunohistochemical results. These findings indicate that higher and longer-term expression of p63 in the hippocampal CA1 region of the young gerbils after ischemia/reperfusion may be related to more delayed neuronal death compared to that in the adults.

CaMKⅡγ和CaMKⅡδ通过PI3K/Akt/Erk信号通路减轻小鼠神经元缺血再灌注损伤

目的观察钙/钙调蛋白依赖性激酶Ⅱ(CaMKⅡ)的同工型CaMKⅡγ和CaMKⅡδ对鼠神经元细胞缺血缺氧再灌注损伤的影响,并探究其作用机制。方法分离胚胎期第18天胎鼠大脑用于提取原代神经元,在5%CO_(2)、37℃条件下培养,分为常规培养的对照组、空白对照组(si-NT)、CaMKⅡγ敲除组(si-CAMK2G)和CaMKⅡδ敲除组(si-CAMK2D)。研究组神经元转染处理后,更换为无糖培养基,并将其置于缺氧环境中模拟氧糖剥夺(OGD/R)条件,持续1 h,随后复原标准培养环境。通过对神经元裂解物行免疫蛋白印迹检测磷脂酰肌醇-3-激酶/细胞外信号调节激酶(PI3K/Akt/Erk)信号通路构件的表达量,并建立小鼠大脑中动脉闭塞(MCAO)模型,通过对比假手术组(Sham)(n=25)和MCAO组(n=25)PI3K/Akt/Erk信号通路表达来进行验证。结果si-CAMK2G组的胎鼠神经元细胞在OGD/R 12、24、48、72 h的生存率明显低于si-NT组(P<0.01或0.001),并可逆转OGD/R介导的胎鼠神经元细胞CaMKⅡγ表达上调。si-CAMK2G组和si-CAMK2D组与si-NT组相比,PI3K/Akt/Erk信号通路表达受到明显抑制(P<0.01)。在MCAO模型中,MCAO组小鼠脑CaMKⅡδ和CaMKⅡγ的表达显著增加并激活了PI3K/Akt/Erk信号通路,CaMKⅡδ和CaMKⅡγ,Erk、磷酸化Erk、Akt和磷酸化Akt在MCAO造模成功再灌注后24、48、72和96 h的表达显著高于Sham组再灌注24 h(P<0.05,0.01或0.0001)。结论CaMKⅡγ和CaMKⅡδ在神经元细胞发生缺血缺氧损伤时的神经保护作用可能是通过PI3K/Akt/Erk信号通路介导的。

Continuous assessment of cerebral autoregulation by TCD during tilt table testing

[SUMMARY] TTTT is a non-invasive and new investigative examination,and a most important method of clinical diagnosis for many diseases,specially for orthostatic syncope,autonomic failure,intracranial hypertension,neurodegenerative diseases,CVAs and so on.At the same time,TCD technique for non-invasive monitoring of CBFV has also provided a new tool for investigating CA.In clinical circumstance,we may carry on assessment of dynamic CA by TTTT,and this kind of method has been proved to be appropriate to examine patients and monitor.we can choose different tilt positions by tilt-table according to the different demands for clinical diagnosis or researches,and record the different appearances of various index signs,we can take advantage of the technique of transfer function analysis of power spectrum between spontaneous changes in CBF and other factors(such as arterial pressure) to do research on the specific mechanism of impaired CA.

黄芪多糖对缺血缺氧脑损伤大鼠脑组织Ca^(2+)和兴奋性氨基酸的影响

目的:探讨黄芪多糖对缺血缺氧脑损伤大鼠脑组织中Ca^(2+)和兴奋性氨基酸水平的影响。方法:60只大鼠随机分成3组:假手术组、模型组、黄芪多糖组,每组20只。采用改良Longa线栓法制备大鼠中动脉栓塞(MCAO)模型。黄芪多糖组于脑缺血前30 min及术后8 h按1g·kg^(-1)分别腹腔注射给药1次,模型组和假手术组于同时间腹腔注射等容量生理氯化钠溶液。3组均于造模24 h后断头取血2 mL,分离血清,并取全脑,测脑组织的Ca^(2+)含量、脑组织和血清中谷氨酸(Glu)和天门冬氨酸(Asp)的含量。结果:模型组脑组织Ca^(2+)、脑组织和血清Glu和Asp含量均明显高于假手术组(P＜0．01),黄芪多糖组这些指标的变化则显著低于模型组(P＜0．01或P＜0．05)。结论:黄芪多糖对缺血缺氧脑损伤大鼠具有脑保护作用,其机制可能与降低脑内Ca^(2+)和兴奋性氨基酸的含量有关。

高压氧对脑缺血及再灌注时海马游离Ca^（2＋）及钙通道的作用

应用新型钙离子荧光指示剂Ｆｕｒａ－２／ＡＭ测定海马突触体内游离Ｃａ￣（２＋）浓度，观察在脑缺血时及不同压力高压氧治疗后的变化规律，并应用［￣３Ｈ］ＰＮ２００－１１０作为放射性配基，用放射配体结合法测定海马组织Ｌ－型钙通道生物学特性和缺血及高压氧治疗后的变化。结果表明：脑缺血及再灌注后海马脑区突触体内游离Ｃａ￣（２＋）浓度显著增加，其Ｌ－型钙通道的Ｂｍａｘ和Ｋｄ值均显著上升，但经吸入高压氧后，可降低胞浆内游离Ｃａ￣（２＋）浓度，其中以２５３．２５ｋＰａ高压氧作用明显，并可降低钙通道的Ｂｍａｘ与Ｋｄ值。说明高压氧部分地通过减少细胞内游离Ｃａ￣（２＋）而起作用，Ｌ－型钙通道参与了高压氧降低脑缺血后胞浆内游离Ｃａ￣（２＋）浓度的作用，高压氧可使其开放的通道数量减少。

桂枝茯苓丸加减方对脑缺血及再灌注过程中Ca^(2+)、氨基酸水平的变化研究

目的：研究桂枝茯苓丸加减方在脑缺血及再灌注模型中血清及脑组织中谷氨酸（Ｇｌｕ）、天冬氨酸（Ａｓｐ）、甘氨酸（Ｇｌｙ）、γ氨基丁酸（ＧＡＢＡ）的变化。同时测定用药前后脑组织中Ｃａ２＋水平变化及脑水肿的程度。方法：氨基酸自动分析仪测定Ｇｌｕ，Ａｓｐ，Ｇｌｙ，ＧＡＢＡ。原子吸收分光光度法测定脑组织中的钙。结果：中药治疗组的氨基酸水平及钙含量与对照组有明显差异。结论：桂枝茯苓丸加减方对缺血性脑损伤有缓解作用。

家兔急性完全性脑缺血及再灌注后山莨菪碱对脑组织[Ca^(2+)]_i和超微结构变化的影响

采用家兔急性完全性脑缺血及再灌注损伤模型 ,观察山莨菪碱对脑组织 [Ca2 +]i和超微结构变化的影响。结果发现 :缺血组及缺血再灌注组脑组织 [Ca2 +]i明显升高 (P<0 .0 1) ,而且缺血再灌注组明显高于缺血组 (P<0 .0 1) ,脑组织超微结构损伤明显加重 ;山莨菪碱治疗组脑组织 [Ca2 +]i较缺血组及缺血再灌注组明显降低 (P<0 .0 1) ,脑组织超微结构损伤亦明显减轻。提示山莨菪碱可能通过 Ca2

纳洛酮对脑缺血大鼠皮层SEP和Ca^(2+)-ATP酶活性的影响

目的 研究纳洛酮对脑缺血大鼠皮层体感诱发电位 (SEP)和Ca2 + ATP酶活性的影响 ,探讨纳洛酮对急性脑缺血损伤的脑保护作用机制。方法 在大鼠大脑中动脉栓塞动物模型基础上 ,侧脑室注射不同剂量纳洛酮 ,以皮层SEP和Ca2 + ATP酶活性为指标 ,观察纳洛酮对脑缺血的作用。结果 脑缺血后 ,皮层SEP主波消失 ,Ca2 + ATP酶活性显著降低 (P <0 .0 0 1 ) ,纳洛酮可在一定程度上恢复SEP(P <0 .0 1 ) ,并使Ca2 + ATP酶活性升高 (P <0 .0 1 )。

脑缺血和再灌注时Ca^（2＋）／CaMPKII活性的变化及苄丙咯的影响

本文以蒙古沙土鼠双侧颈总动脉结扎造成脑缺血模型，研究了脑缺血和再灌注时大脑Ｃａ￣２＋／ＣａＭＰＫⅡ活性变化及苄丙咯对其活性的影响，实验结果：（１）Ｃａ￣２＋／ＣａＭＰＫⅡ活性随脑缺血时间的延长而逐渐降低，脑缺血１０分钟，酶活性显著低于正常组（Ｐ＜０．０１）；（２）脑缺血１０分钟再灌注２０分钟，酶活性部分恢复，与缺血１０分钟组相比，酶活性有明显上升（Ｐ＜０．０１），但缺血２０分钟再灌注，其活性不再恢复；（３）缺血前２０分钟腹腔注射苄丙咯，在缺血１０分钟时酶活性明显高于对照组（Ｐ＜０．０ｌ）。结果提示Ｃａ￣２＋／ＣａＭＰＫⅡ活性对缺血非常敏感；苄丙咯对该酶活性有一定保护作用。

三七总皂甙对缺血再灌注鼠脑组织Ca^(2+)和兴奋性氨基酸的影响

目的 :探讨Ca2 +、兴奋性氨基酸在缺血再灌注鼠脑损伤中的作用及三七总皂甙对其影响。方法 :对缺血再灌注鼠脑组织Ca2 +、氨基酸及血清氨基酸分别进行测定 ,并观察三七总皂甙对其影响。结果 :模型组脑组织Ca2 +、脑和血清谷氨酸 (Glu)、天门冬氨酸 (Asp)、甘氨酸 (Gly)、γ 氨基丁酸 (GABA)高于正常动物组 ,三七总皂甙组低于模型组。结论 :Ca2 +、氨基酸参予再灌注脑损伤的病理过程 ,而三七总皂甙可能通过降低脑内Ca2 +、降低兴奋性氨基酸(EAA)

地黄煎剂抑制异丙肾上腺素诱发的缺血大鼠脑Ca^(2+),Mg^(2+)-ATP酶活力升高

正常大鼠脑组织Ca^(2+),Mg^(2+)-ATP酶活力为2.8±0.7 μmol/Pi mg protein·h。大鼠ip异丙肾上腺素5mg/kg 24h造成脑缺血,其Ca^(2+),Mg^(2+)-ATP酶活力升高至8.8±0.8 μmol/Pi mg protein·h。经地黄2或4g/kg po给药后,大鼠缺血脑Ca^(2+),Mg^(2+)-ATP酶活力分别降至6.8±0.8和5.8±0.7 μmol/Pj mg protein·h,表明地黄可防止脑组织缺血损伤和ATP耗竭,提示地黄中可能含有钙拮抗活性物质。

山莨菪碱对家兔急性完全性脑缺血及再灌流后脑组织[Ca^(2+)]_i和超微结构影响

目的 研究山莨菪碱对急性完全性脑缺血及再灌注后脑组织游离Ca2 + ([Ca2 + ]i)及超微结构的影响。方法 采用闭塞双侧颈总动脉和椎动脉及体循环低血压法建立家兔急性完全性脑缺血及再灌流损伤模型 ,缺血 2 0min ,再灌流 2h。40只家兔随机分为假手术组、缺血组、缺血再灌流组、治疗组 ,观察了脑组织 [Ca2 + ]i和超微结构及山莨菪碱对其变化的影响。结果 缺血组及缺血再灌流组脑组织 [Ca2 + ]i 浓度明显高于假手术组 (P <0 0 1) ,而且缺血再灌流组 [Ca2 + ]i 明显高于缺血组(P <0 0 1) ,随着 [Ca2 + ]i 增加 ,脑组织超微结构损伤明显加重。治疗组 [Ca2 + ]i 浓度较缺血组及缺血再灌流组明显降低 (P <0 0 1) ,同时脑组织超微结构损伤明显减轻。结论 山莨菪碱通过阻断Ca2 + 内流对完全性脑缺血及再灌损伤具有保护作用。