脑缺血早期大脑皮质和尾壳核一氧化氮合酶神经元的进程变化

目的：探讨一氧化氮合酶神经元在脑缺血早期（２４ｈ内）的变化规律。方法：ＮＡＤＰＨ－ｄ组织化学方法。结果：各组间正常侧ＮＯＳ神经元无明显变化，散在分布于皮质的Ⅱ～Ⅵ层，以Ⅳ～Ⅵ为主，尾壳核内ＮＯＳ神经元数量较多，密集分布于外侧区。缺血１５ｍｉｎ和３０ｍｉｎ组，缺血中心区皮质和尾壳核ＮＯＳ神经元数量减少，形态无明显变化；缺血１ｈ和２ｈ组，皮质和尾壳核内ＮＯＳ神经元数量进一步减少，突起变短；缺血３ｈ和６     

川芎嗪对大鼠脑缺血再灌注损伤后大脑皮质Bc1-2表达的影响

目的:研究川芎嗪对大鼠脑缺血再灌注损伤后Bcl-2表达的影响.方法:以线栓法制作大鼠大脑中动脉阻塞的局灶性脑缺血再灌注模型,采用免疫印迹、2, 3, 5-氯化三苯四氮唑(TTC)、 H-E染色和神经行为相结合的方法,观测缺血再灌注侧大脑皮质内Bcl-2的表达、脑梗塞体积、脑组织结构及神经功能的变化.结果:与缺血再灌注组(I 2h/R24h)比较,川芎嗪组的Bcl-2表达明显增高,脑梗塞体明显缩小,脑组织的病理损伤和神经异常行为明显减轻.结论:川芎嗪可通过上调Bcl-2的表达,缩小脑梗塞的体积和减轻脑缺血区组织结构的损伤以及明显改善神经症状,对脑缺血再灌注损伤有保护作用.     

脑缺血大鼠大脑皮质NMDA受体的早期表达

目的　探讨脑缺血和缺血再灌注早期大脑皮质NMDA受体的变化规律。方法　健康雄性SD大鼠 4 8只 ,随机分为 6组 :假手术对照组、单纯脑缺血 1 5min、2 0min和 30min组及脑缺血 1 5min再灌流 30min和 2 4h组 ;4血管脑缺血动物模型 ;连续冰冻冠状切片观察 ,NR1 免疫组化染色特异性地显著NMDA受体的变化 ,图象分析及计算阳性单位PU值。结果　①单纯脑缺血各组PU值分别为 7 5 5± 1 81、6 91± 2 5 3和 6 0 9± 1 5 0 ,与对照组PU值 9 0 4± 1 5 7相比呈下降趋势 (P≤ 0 0 5 ) ;②再灌流 30min和 2 4h组PU值分别为 5 76± 2 2 4和 4 73± 1 34,与对照组PU值相比明显减少 36 2 9%～ 4 7 6 8% ,有统计学意义(P <0 0 5 ) ;③再灌流 0min、30min和 2 4h组两两比较 ,除 2 4h和 0min组相比NR1 阳性反应物减少有统计学意义 (P <0 0 5 )外 ,其它组别间NMDA受体下降的变化无显著性差异 (P >0 0 5 )。结论　脑缺血和缺血再灌流早期NMDA受体都存在下行调节 ,这种调节可能是一种保护性作用     

脑缺血对大鼠大脑皮质中钙通道Cav1.3表达的影响

目的:探讨脑缺血后大鼠大脑皮质中钙通道Cav1.3表达变化及其在脑缺血损伤中的作用机制。方法:雄性Wistar大鼠随机分为假手术组、缺血7 d组和缺血14 d组。采用免疫组织化学和免疫印迹分别检测各组大鼠大脑皮质中钙通道Cav1.3的表达,采用TUNEL法观察大鼠大脑皮质内细胞的凋亡。结果:与假手术组比较,缺血7 d和14 d组大鼠大脑皮质中钙通道Cav1.3免疫组织化学显色的平均光密度(OD)值和免疫印迹条带的IOD比值都明显降低,缺血14 d组较7 d组降低更明显,细胞凋亡检测显示大脑皮质中凋亡神经元数量随缺血时间延长而增加。结论:缺血导致神经元凋亡的机制可能通过影响钙通道Cav1.3的表达,从而影响皮质神经元的正常功能,导致神经元死亡。     

脑缺血不同时间大鼠海马神经元损伤的形态学变化

目的：探讨存不同的缺血时间段大鼠海马神经元受损的形态学变化。以期为相关疾病发病机制的研究和临床治疗提供新的思路。方法：通过双侧颈总动脉水久性结扎的18月龄大鼠脑缺血模型。采用HE染色、尼氏染色、TUNEL染色和电镜观察等方法对脑缺血5、30、60、90d组海马神经元形态及细胞凋亡情况进行比较分析。结果和结论：大鼠脑缺血时间与海马神经元损伤程度密切关系。     

阿魏酸及其酯化产物与体外培养大鼠大脑皮质神经元的存活

背景：大量体外筛选中得到的中药脑神经保护活性成分,多因脂溶性低难以透过血脑屏障而限制了其临床应用。 目的：比较阿魏酸及其酯化产物阿魏酸甲酯、乙酯对原代培养的大鼠大脑皮质神经元体外存活的保护作用。 方法：出生1 d内的乳鼠采用酶消化法分离培养大脑皮质神经元。培养6 d后,分别进行阿魏酸、阿魏酸甲酯及乙酯干预,继续培养1 d。 结果与结论：形态学观察结果显示细胞生长良好,NSE染色检查表明培养6 d的存活细胞大部分均为神经元。MTT比色法测量结果显示,与空白对照组比较,阿魏酸仅在质量浓度为200 mg/L时有明显促进大脑皮质神经元存活的作用,而阿魏酸甲酯、乙酯在质量浓度为0.16~20 mg/L时均能明显促进神经元体外存活,且作用趋势、作用强度相近。表明阿魏酸的酯化产物阿魏酸甲酯和阿魏酸乙酯均能促进原代培养的大脑皮质神经元体外存活,显示出较好的脑神经元保护作用,且活性比阿魏酸更强。     

电针水沟、百会穴对脑缺血再灌注损伤大鼠大脑皮质神经元凋亡的影响

背景:脑缺血再灌注损伤常见于缺血性脑卒中,严重影响患者预后,因此探索有效缓解脑缺血再灌注损伤的治疗方法十分重要。电针可有效改善缺血性脑卒中神经功能的缺损症状。目的:探讨电针治疗对脑缺血再灌注损伤大鼠的神经保护作用及其对大脑皮质神经元凋亡的影响。方法:将48只雄性3月龄的SD大鼠随机分为假手术组、模型组、电针组,每组16只。模型组及电针组所有大鼠进行左侧大脑中动脉脑缺血再灌注造模,缺血2 h,再灌注6 h;假手术组大鼠仅暴露并游离颈动脉。然后对电针组大鼠进行“水沟”“百会”穴的电针干预,选择疏密波,频率3 Hz/15 Hz,强度1 mA,干预20 min,1次/d,连续5 d。模型制作后第5天,使用Longa神经功能评分对所有纳入实验的大鼠进行神经功能受损程度评定;TTC染色观察脑梗死体积;ELISA法检测炎症因子水平;TUNEL法检测细胞凋亡情况;荧光定量PCR及Western blot分别检测大脑皮质区半胱天冬氨酸蛋白酶3(Caspase-3)、半胱天冬氨酸蛋白酶8(Caspase-8)mRNA及蛋白的表达水平。结果与结论:(1)与假手术组相比,模型组大鼠神经功能评分明显升高(P<0.01);脑梗死体积明显增大(P<0.01);左侧大脑皮质区TUNEL阳性细胞数量明显增多(P<0.01);血清炎症因子白细胞介素1β、白细胞介素18、肿瘤坏死因子α表达水平升高(P<0.05,P<0.01,P<0.01);大脑皮质区Caspase-3、Caspase-8 mRNA及蛋白表达水平明显升高(P<0.01,P<0.01);(2)与模型组相比,电针组大鼠神经功能评分降低(P<0.05);脑梗死体积减小(P<0.05);左侧大脑皮质区TUNEL阳性细胞数量明显减少(P<0.01);血清炎症因子白细胞介素1β、白细胞介素18、肿瘤坏死因子α表达水平均降低(P<0.01,P<0.05,P<0.05);大脑皮质区Caspase-3、Caspase-8 mRNA及蛋白表水平明显降低(P<0.01,P<0.01);(3)提示电针治疗可能通过抑制大鼠大脑皮质神经元凋亡,缓解脑缺血再灌注损伤,发挥神经保护作用。     

CREB与脑缺血神经元损伤

cAMP反应元件结合蛋白(CREB)是位于细胞核内的转录因子,在脑缺血缺氧保护机制中起到了十分重要的作用。在脑缺血缺氧后,CREB通过多种途径被激活,再通过激活下游抗凋亡因子(如BDNF、Bcl-2+2等)及参与阻止Ca内流等多种途径起到保护神经元作用。     

bFGF对成年大鼠损伤的大脑皮质神经元的作用

实验用ＳＤ大鼠４０只，其中３０只分为实验组和对照组各１５只，切片用甲基绿－派洛宁染色；另１０只也分为实验组和对照组，各５只，切片用神经丝免疫组化染色．手术毁损大鼠大脑顶叶皮质，立即放入分别浸有碱性成纤维细胞生长因子（实验组）或ＰＢＳ（ｐＨ７．２，０．２ｍｏＬ／Ｍ）（对照组）的海绵胶粒（１ｍｍ３），于术后１４ｄ，２４ｄ，３４ｄ在损伤的皮质腔内重复注射相应的实验用液２５μｌ．术后４０ｄ取材，在大脑皮质损伤腔颞侧边缘Ⅱ～Ⅲ层距边缘５００μｍ范围内，对每只大鼠计数了１ｍｍ２面积中的存活神经元数目，并观察神经元的形态学变化．结果发现，实验组大脑皮质存活神经元数目较多，对照组存活神经元较少．经体视学定量方法分析，结果其均数±标准差为：实验组９１９．４５±１６５．４０，对照组６２８．３９±５７．５０／ｍｍ２，经两样本均数ｔ检验，Ｐ＜０．０５．提示碱性成纤维细胞生长因子对大鼠大脑皮质损伤神经元有一定的维持存活作用．     

高血脂对大鼠脑缺血再灌注损伤后大脑皮质p38丝裂原活化蛋白激酶表达的影响

目的:检测高血脂对脑缺血再灌注损伤后缺血侧大脑皮质p38丝裂原活化蛋白激酶(p38MAPK)表达的影响。方法:喂食高脂饲料建立高血脂动物模型,随后线栓法建立脑缺血再灌注模型。Zea-Longa神经行为学评分法记录大鼠神经行为改变,TTC染色检测脑梗死灶体积,免疫组织化学及免疫印迹检测大脑皮质p38MAPK表达水平。结果:高血脂脑缺血再灌注后神经行为损伤加重,且梗死灶体积较单纯脑缺血再灌注明显扩大。与假手术组比较,单纯脑缺血再灌注组和高血脂脑缺血再灌注组大脑皮质p38MAPK表达明显增加,再灌注2 h时其表达量即开始增高,再灌注24 h时达高峰,而后又降低。相同再灌注时间点,与单纯脑缺血再灌注组比较,高血脂脑缺血再灌注组p38MAPK表达增高。结论:高血脂脑缺血再灌注损伤中,高血脂可上调大脑皮质p38MAPK表达,促进细胞凋亡的发生及加重炎症反应,进而加重缺血再灌注损伤。     

Cyclic AMP in the organs and tissues during adaptation to extremal factors

Extremal factors of different nature (hypoxic hypoxia, carbon monoxide poisoning, exposure to chemicals and to noise, hypokinesia) caused similar changes in the cyclic AMP level in the organs of albino rats (liver, cerebral hemispheres, heart). A considerable increase in the cyclic AMP concentration was found in the first stages, followed by a progressive fall during subsequent exposure, especially if the intensity of the factor was high. It is suggested that the universality of this response reflects one of the central adaptive mechanisms of the cell and of the organism as a whole.Leningrad Pediatric Medical Institute. (Presented by Academician S. E. Severin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 11, pp. 567–568, November, 1977.     

Impaired Monocyte Cyclic AMP Responses and Monocyte Cytotoxicity in Atopic Dermatitis

Purified monocytes from 21 patients with mild and severe atopic dermatitis (AD) were compared with 22 healthy controls with respect to antibody-dependent cell-mediated cytotoxicity (ADCC) and cyclic adenosine 3',5'-monophosphate (cAMP) responses to stimulatory agents. ADCC was depressed in both severe and mild atopic dermatitis. The patients showed decreased cAMP responses to isoproterenol and histamine, the decrement being more distinct in severe atopic dermatitis. Formation of cAMP was diminished with PGE, only in patients with severe AD. ADCC is inhibited by the agents that increase cAMP. In the severe dermatitis group reduced inhibition induced by isoproterenol, histamine, but not PGE₁, was obtained. It is suggested that a general suppression of membrane activation may explain the reduced cAMP responses to various stimulatory agents and the impaired monocyte cytotoxicity.     

Cyclic AMP content in some structures of the limbic system in rats treated with corticosteroids

The effect of hydrocortisone and deoxycorticosterone acetate (DOCA) on the content of cyclic AMP in the hypothalamus, hippocampus, and corpus striatum was studied in rats. Single (determination after 1 and 24 h) and repeated (7 days) injection of hydrocortisone in a dose of 5 mg/100 g body weight was followed by an increase in the cyclic AMP concentration in these brain structures. After a single injection of DOCA in a dose of 0.5 mg/100 g body weight no change was found in the cyclic AMP level in structures of the limbic system in rats, but an increase in the cyclic AMP concentration was found after a dose of 2.5 mg. Prolonged administration of the hormone in these doses caused no changes in the cyclic AMP level in the brain structures tested. Only in the hippocampus was an increase in the cyclic AMP concentration by 210% observed after injection of 0.5 mg DOCA.Laboratory of Neurochemistry, Kiev Research Institute of Endocrinology and Metabolism, Ministry of Health of the Ukrainian SSR. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 2, pp. 139–141, February, 1980.     

Production of Leukotrienes in Human Skin and Conjunctival Mucosa after Specific Allergen Challenge

The production of leukotrienes has been monitored in tear fluids from subjects following a conjunctival provocation test, and skin blister fluids following initiation of a Prausnitz-Kustner reaction. In tear fluids elevated levels of leukotriene C4 (LTC4)-immunoreactive material were measured following allergen challenge as compared to control tear fluid obtained by mechanical or reflex stimulation. Analysis by high performance liquid chromatography indicated the presence of LTC4, LTD4 and LTE4. In the skin, significantly elevated levels of LTC4-immunoreactive material were measured following allergen challenge in the Prausnitz-Kustner reaction. HPLC analysis indicated the presence of both LTC4 and LTD4. LTB4 immunoreactive material was detected both in the tear fluid and the skin tissue fluid. However, no significant increase occurred in either tissue after the allergic reactions. These results indicate that the SRS-A leukotrienes are released in vivo in man following allergen challenge, and indicate these mediators may be important in human allergic diseases.     

Cyclic AMP and adenyl cyclase in the developing rat brain

The level of endogenous cyclic AMP in the rat brain in vivo began to increase markedly between the third and sixth days after birth, as did the ability of norepinephrine to stimulate the formation of cyclic AMP in brain tissue in vitro. Adenyl cyclase activity in broken cell preparations, when measure in the absence of sodium fluoride, increased with age up to a point, but began to decline between the fifth and ninth days postpartum. Activity continued to increase when measured in the presence of fluoride, suggesting that the apparent stimulatory effect of this ion may in fact be the reversal of an inhibitory influence which is absent or almost absent at birth. Cyclase activity at all ages was restricted to particulate matter, whereas apparent phosphodiesterase activity was present in particulate as well as soluble fractions. The catabolic system for cyclic AMP developed in a similar manner in both fractions. Theophylline produced the same degree of inhibition of this system at all ages.     

Cyclic AMP metabolism in the liver of newborn rats after irradiation during organogenesis

The level of adenylate cyclase (AC) and phosphodiesterase (PDE) activity and the reserves of cyclic AMP in the liver of newborn rats were investigated in normal animals and after irradiation on the 9th day of embryonic development. After irradiation in a dose of 50 R the basal AC and PDE activity was reduced, but there was no change in the steady-state cyclic AMP content in the tissues. The adrenalin-stimulated AC activity showed only a tendency to fall after irradiation. It is suggested that at critical moments of development, when the hormonal inducer is present in the liver of irradiated animals the conditions may be created for an increase in the cyclic AMP reserves.Laboratory of Molecular Radiobiology, Institute of Biological Physics, Academy of Sciences of the USSR, Pushchino. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 7, pp. 91–93, July, 1978.     

Adenosine in Rat Cerebral Cortex: Its Determination,Normal Values,and Correlation to AMP and Cyclic AMP during Shortlasting Ischemia

It has recently been suggested that adenosine is a metabolic coupling factor responsible for an increased cerebral blood flow during hypoxia or increased functional activity. However, tissue adenosine concentrations have been reported to increase in situations previously shown to be unassociated with changes in tissue AMP concentrations. The present experiments were undertaken to assess cerebral cortex concentrations of adenosine under normal circumstances, and to relate changes in adenosine, AMP and cyclic AMP during shortlasting ischemia. Following freezing and extraction of tissue, adenosine was measured using high pressure liquid chromatography. In paralyzed and anaesthetized (70% N₂O) rats, freezing of tissue through intact skull bone gave an adenosine concentration of 0.9 ± 0.1 μmol·kg^-1 (mean±S.E.M). With freezing through the exposed dura the concentration was 3 times as high with a large scatter. When special precautions were taken to avoid tissue trauma during craniotomy, the adenosine concentration was 1.1 ± 0.1 μmol·kg^-1. It is concluded that previously reported values are erroneously high. During the first 60 s of total ischemia there was a linear correlation between increase in AMP and in adenosine concentration (as well as between adenosine and cyclic AMP concentrations). It is concluded that increases in tissue adenosine concentration only occur if AMP accumulates. However, since (relative) changes in adenosine concentrations are at least twice those of AMP, analyses of adenosine may provide sensitive measures of a change in phosphorylation state.     

Changes in the nucleic acid and cyclic AMP content in neurogenic dystrophies of the stomach

A decrease in the RNA content was found in the stomach tissue of rats following degenerative changes in the organ induced by injury to the duodenum. A sharp fall in the cyclic AMP level in the gastric mucosa of rabbits was found under the same experimental conditions. The role of these changes in the mechanism of development of destructive and metabolic disturbances during the formation of neurogenic dystrophies caused by extraordinary stimulation is analyzed.Laboratory of Experimental Pharmacology, Department of Pharmacology, Institute of Experimental Medicine, Academy of Medical Sciences of the USSR, Leningrad. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 4, pp. 405–407, April, 1978.