脑室注射BDNF对抑郁症大鼠海马神经元前体细胞微管相关蛋白Doublecortin表达的影响

目的 探讨脑源性神经营养因子(brain-drived neurotrophic factor,BDNF)对抑郁症大鼠海马神经元前体细胞微管相关蛋白Doublecortin(DCX)表达的影响,为BDNF如何影响神经元前体细胞的增殖、迁移提供实验依据.方法 成功建立抑郁症大鼠模型后,向脑室注射0.5 μg BDNF,取脑组织行冰冻切片.采用免疫组织化学和免疫荧光技术观察DCX阳性细胞表达情况及表达部位.结果 相对于未注射BDNF的抑郁症大鼠,注射组大鼠海马区域DCX阳性细胞数明显增多,且与未注射组存在明显差异(P＜0.05).结论 BDNF可能通过调控抑郁症大鼠海马神经元前体细胞微管相关蛋白DCX的表达,从而影响抑郁症时神经元前体细胞的分化和迁移.     

脑室内注射重组BDNF腺病毒对大鼠海马神经发生的影响

目的 观察脑室内注射BDNF对海马神经发生的影响.方法 脑室内注射重组BDNF腺病毒4周后,Morris 水迷宫进行行为学检测,双标组化染色方法观察海马新生神经元数目的 变化.结果 与对照组相比,实验组大鼠空间学习和记忆能力明显增强(P<0.05);实验组大鼠海马DG区Brdu/DCX阳性神经元数目明显多于对照组(P<...     

短期运动训练对自发性高血压大鼠海马BDNF通路的影响

目的 探讨短期运动训练对自发性高血压大鼠海马脑源性神经营养因子(BDNF)通路的影响.方法 分别将自发性高血压(SHR)大鼠和同源正常血压(WKY)大鼠分为非运动组和运动组,每组15只.运动组大鼠每天进行持续30min的运动,连续21d.非运动组大鼠在相同时间段被关在跑步机附近的笼子里.采用酶联免疫吸附和Western...     

噪声对大鼠学习记忆中海马区NOS阳性神经元表达的影响

目的：拟在白噪声下观察对大鼠学习记忆的影响及海马区NOS的变化，探讨噪声所致大鼠学习记忆下降的机制。方法：44只SD大鼠，其中20只随机分两组，分别在持续80dB(A)白噪声和无噪声的环境下，在Y—迷宫中进行空间辨别学习记忆训练，了解噪声对大鼠学习记忆的影响，另24只大鼠随机分三组：噪声训练组、正常训练组和噪声观察组，以同样的方法训练，用免疫组化的方法观察持续噪声对海马区NOS阳性神经元表达变化。结果：噪声能降低大鼠学习记忆能力，而且海马区NOS阳性神经元较正常对照组的数量及染色强度显著降低。结论：噪声降低海马区神经元活性，NOS的合成减少，抑制海马习得性长时程突触增强，影响记忆的获得与保持，延迟短时记亿向长时记忆的转化。     

葛根素对血管性痴呆大鼠海马锥体细胞和BDNF表达的影响

为了观察葛根素对血管性痴呆(VD)模型大鼠海马锥体细胞和BDNF表达的影响及其作用机制,本研究采用双侧颈总动脉缺血再灌注,同时腹腔注射硝普钠建立血管性痴呆大鼠模型,选出造模成功者随机分为模型组及葛根素干预组,各为24只,另以条件匹配的24只大鼠为假手术组。分别在造模术后15d,1、2和4个月等时间点,采用水迷宫检测大鼠学习记忆能力的变化,HE染色和免疫组化染色观察大鼠海马神经元的形态学改变及BDNF表达的变化。结果显示:(1)模型组大鼠的逃逸潜伏期(EL)均明显长于假手术组(P<0.01),葛根素干预组大鼠的EL较模型组明显缩短(P<0.05),但仍长于假手术组(P<0.05);(2)模型组大鼠海马CA1区锥体细胞数比假手术组明显减少(P<0.01),葛根素干预组2个月和4个月时点锥体细胞数较模型组明显增多(P<0.01),但仍少于假手术组(P<0.01);(3)模型组大鼠海马BDNF阳性细胞明显减少(P<0.01),除15d和1个月组DG区外,葛根素干预组大鼠海马BDNF阳性细胞数较模型组明显增多(P<0.05),但仍低于假手术组(P<0.05);(4)模型组大鼠海马BDNF阳性细胞平均吸光度值较假手术组明显降低(P<0.01),而葛根素干预组比模型组和假手术组均明显降低(P<0.05)。本研究结果提示,脑缺血再灌注后,海马BDNF阳性神经元和锥体细胞持续减少,在VD学习记忆障碍的发生和发展过程中起重要作用;葛根素对脑缺血再灌注损伤具有保护作用,其机制可能与葛根素上调BDNF的表达、减少锥体细胞的丢失有关。     

侧脑室注射PP2对慢性复合应激大鼠学习记忆功能和海马内Fyn、BDNF和TrkB表达的影响

为了探讨酪氨酸激酶抑制剂PP2对慢性复合应激性学习记忆增强大鼠的学习记忆功能和海马内非受体酪氨酸激酶(Fyn)、脑源性神经营养因子(BDNF)和Trk酪氨酸激酶B(TrkB)表达的影响,本实验将成年雄性大鼠22只,随机分为三组:即慢性复合应激组(对照组)、慢性复合应激+注射盐水组(盐水组)和慢性复合应激+注射PP2组(PP2组)。全部动物暴露于复合应激原中6周后,盐水组和PP2组动物分别侧脑室注射生理盐水或PP2(1次/d,共11d)。实验结束后,用Morris水迷宫测试大鼠的空间学习记忆成绩;采用免疫组织化学方法检测Fyn、BDNF和TrkB在海马内蛋白表达的变化。结果显示:与对照组和盐水组相比,PP2组动物的学习与记忆成绩明显下降(P<0.05);海马内Fyn和BDNF蛋白阳性表达减弱(P<0.05);但3组动物海马内TrkB的蛋白表达无显著性差异(P>0.05)。上述结果表明:侧脑室注射PP2可抑制大鼠慢性复合应激性学习记忆能力的增强作用,下调Fyn和BDNF在海马内的表达;提示Fyn和BDNF/TrkB信号转导途径在慢性复合应激增强大鼠学习记忆能力的过程中发挥重要作用。     

BDNF对慢性应激性大鼠海马神经元损伤的保护作用

目的研究脑源性神经营养因子(BDNF)对大鼠海马神经元的保护作用。方法40只成年Wistar大鼠随机分为对照组、应激组、BDNF低剂量组和高剂量组,每组10只。用电击足底结合噪声建立慢性应激大鼠模型,Morris水迷宫观察动物的空间学习和记忆能力,Nissl染色观察和计数海马神经元数量,Fara-2荧光法测海马突触体内游离钙浓度。结果在双海马注射BDNF后,对于因慢性应激引起的空间学习和记忆能力下降,海马神经元数量减少,海马突触体内游离钙浓度增高有明显保护作用。结论BDNF对应激海马损伤有保护作用,其机制可能是通过调节海马细胞内的钙浓度,防止海马神经细胞丢失有关。     

MK-801对皮质酮诱导 抑郁样行为大鼠海马mBDNF和proBDNF表达的影响

目的 N-甲基-D-天冬氨酸(NMDA)受体拮抗剂通过脑源性神经营养因子(BDNF)发挥抗抑郁作用.然而,NMDA受体拮抗剂调控BDNF表达的机制尚不清楚.方法 口服皮质酮(CORT)诱导大鼠抑郁样行为.采用高架十字迷宫实验、蔗糖偏好实验、旷场实验和强迫游泳实验观察动物的抑郁样行为,采用蛋白免疫印迹方法检测动物背侧和腹...     

不同负重游泳训练对大鼠肾上腺BDNF和trkB表达的影响

目的 探讨不同负重游泳训练对肾上腺BDNF及受体TrkB表达的影响.方法 成年SD大鼠分三组即轻负重组(体重的1％),中负重组(3％)和中负重组(5％).用水槽进行游泳训练.最后用水迷宫记录大鼠游泳轨迹,测定游泳速度,同时用RT-PCR检测肾上腺BDNF及TrkB水平.结果 中负重组游泳速度较其它两组有加快,肾上腺BDNF表达没有发生改变,而TrkB在中负重组已明显下调,与其它两组比差异有统计学意义(P＜0.05).结论 负重游泳后中度负重导致肾上腺TrkB表达下调,但对BDNF表达没有明显影响.     

缺氧诱导因子-1在缺氧诱导一氧化氮合成酶基因表达中的作用

目的 研究缺氧诱导因子-1(HIF-1)在一氧化氮合成酶基因缺氧诱导反应中的作用。方法 体外合成具有HIF-1特异结合位点的DNA片段(红细胞生成素3'-增强子片段),借助脂质体,转入培养的鼠主动脉内皮细胞和肺微血管细胞,用半定量RT-PCR方法测定诱导型一氧化氮合成酶(iNOS)mRNA。结果 (1)大鼠主动脉内皮细胞、肺微血管内皮细胞在常氧下培养,有iNOS基因表达;(2)缺氧能诱导这两种细胞iNOS基因表达增加;(3)野生型EPO3'-增强子片段能阻断缺氧对内皮细胞iNOS基因表达的诱导作用,而突变片段则无此作用。结论 在iNOS基因序列中,可能存在EPO3'-端增强子片段,其参与内皮细胞的缺氧反应。     

慢性疲劳应激对大鼠伏隔核一氧化氮合酶表达的影响

目的:探讨长时间游泳引起的疲劳应激对大鼠伏隔核(NAc)中神经元型一氧化氮合酶(nNOS)表达的影响.方法:采用成年雄性大鼠连续4周每天强迫游泳至力竭,用免疫组织化学方法结合图像处理测定伏隔核中nNOS的表达.结果:长时间强迫游泳应激可使大鼠伏隔核巾nNOS免疫细胞化学反应阳性神经元的数量(106.7%)、面积(150.2%)和灰度值(11.3%)显著增加.结论:nNOS参与疲劳应激的形成,一氧化氮在伏隔核对应激调节中起重要作用.     

巨噬细胞诱导型一氧化氮合酶的表达调节机制

一氧化氮是一种重要的巨噬细胞免疫效应分子,它参与免疫调节和宿主防御反应.一氧化氮的生成主要由诱导型一氧化氮合酶调节,然而诱导型一氧化氮合酶表达的调节机制及信号通路尚不完全清楚.     

Expression and cell localization of brain-derived neurotrophic factor and TrkB during zebrafish retinal development

Brain‐derived neurotrophic factor (BDNF) signaling through TrkB regulates different aspects of neuronal development, including survival, axonal and dendritic growth, and synapse formation. Despite recent advances in our understanding of the functional significance of BDNF and TrkB in the retina, the cell types in the retina that express BDNF and TrkB, and the variations in their levels of expression during development, remain poorly defined. The goal of the present study is to determine the age‐dependent changes in the levels of expression and localization of BDNF and TrkB in the zebrafish retina. Zebrafish retinas from 10 days post‐fertilization (dpf) to 180 dpf were used to perform PCR, Western blot and immunohistochemistry. Both BDNF and TrkB mRNAs, and BDNF and full‐length TrkB proteins were detected at all ages sampled. The localization of these proteins in the retina was very similar at all time points studied. BDNF immunoreactivity was found in the outer nuclear layer, the outer plexiform layer and the inner plexiform layer, whereas TrkB immunoreactivity was observed in the inner plexiform layer and, to a lesser extent, in the ganglion cell layer. These results demonstrate that the pattern of expression of BDNF and TrkB in the retina of zebrafish remains unchanged during postembryonic development and adult life. Because TrkB expression in retina did not change with age, cells expressing TrkB may potentially be able to respond during the entire lifespan of zebrafish to BDNF either exogenously administered or endogenously produced, acting through paracrine mechanisms.     

The expression and activity of renal nitric oxide synthase and circulating nitric oxide in polycystic kidney disease rats

Nitric oxide (NO) influences tubular fluid and electrolyte transport, and hence possibly also fluid accumulation in renal cysts. The expression and activity of intrarenal constitutive NO synthase (cNOS) [neuronal NOS, nNOS and endothelial NOS, eNOS] and inducible NOS (iNOS) and plasma nitrite/nitrate (PNOx) concentration were assessed in homozygous Han:SPRD polycystic kidney disease (PKD) rats (cy/cy), heterozygous Han:SPRD PKD rats (cy/+), homozygous normal Han:SPRD littermates (+/+) and Sprague Dawley rats (sd). The results showed: 1) nNOS expression was decreased in proximal tubules and thick ascending limbs of the loop of Henle in cy/cy and cy/+ rats compared to +/+ and sd rats (p<0.05). nNOS was weakly expressed in the epithelium of small cysts and unexpressed in epithelium of large cysts. 2) iNOS expression was increased in proximal tubular epithelial cells in cy/+ rats compared to +/+ rats and sd rats (p<0.01). iNOS expression in cyst epithelium was decreased in cy/+ rats (p<0.05) and absent in cy/cy rats. 3) eNOS expression was similar in the endothelium of intrarenal arteries in all groups. 4) The activity of renal cNOS was decreased in cy/cy and cy/+ rats; the activity of iNOS was decreased only in cy/cy rats, with no significant difference among the other three groups. 5) PNOx concentration was higher in cy/cy rats than in the other three groups, and correlated positively with plasma creatinine and urea. In conclusion, NOS expression and activity decreased as cysts developed, suggesting that NO downregulation is involved in the pathogenesis of PKD.     

内皮型、诱导型一氧化氮合酶在乳腺癌中的表达

目的 :研究内皮型一氧化氮合酶 (eNOS)、诱导型一氧化氮合酶 (iNOS)在乳癌中表达及与淋巴结转移的关系。方法 :采用免疫组化S P法检测 60例乳癌中eNOS和iNOS的表达。结果 :eNOS和iNOS阳性在乳癌中表达率分别为 75 0 %和71 7%。在淋巴结转移组和无淋巴结转移组中eNOS阳性表达率分别为 66 7%和 83 3 % ,两组间差异无统计学意义 (χ2 =2 2 2 ,P >0 0 5) ,而iNOS在淋巴结转移和无转移组中阳性表达率分别为 53 3 %和 90 0 % ,两组间差异有统计学意义 (χ2 =9 93 ,P <0 0 1 )。结论 :内皮型、诱导型一氧化氮合酶在乳腺癌中高表达 ;iNOS的表达与乳腺癌的淋巴转移相关     

束缚应激对大鼠血小板-氧化氮释放的影响

目的 观察急性应激对大鼠血小板一氧化氮(NO)释放的影响及其机制.方法 大鼠浸水-束缚应激(WRS)2、4和8 h,以胃溃疡指数(UI)作为应激损伤的标识,采用Greiss法测定血小板孵育液中亚硝酸盐(NO2-)含量;同位素法测其一氧化氮合酶(NOS)活性和L精氨酸(L-Arg)转运量.结果 WRS 2 h血小板L-Arg转运量、NOS活性和孵育液NO2-含量较对照组显著增加,但随应激时间延长,其呈下降趋势,应激8 h时均显著低于对照组,胃溃疡逐渐加重.结论 WRS应激早期阶段可上调血小板L-Arg/NO通路,促进血小板NO生成;长时间应激下调L-Arg/NO通路,减少NO释放.     

Endothelial nitric oxide synthase gene polymorphism in women with idiopathic recurrent miscarriage

BACKGROUND: Lack of endothelium-derived nitric oxide is associated with vasospasm and vascular infarction. We investigated the relationship between idiopathic recurrent miscarriage and a polymorphism of the gene encoding endothelial nitric oxide synthase (NOS3). METHOD: In a prospective case-control study, 105 women with idiopathic recurrent miscarriage and 91 healthy controls were investigated. We used the polymerase chain reaction to identify the different alleles of a 27 base pair tandem repeat polymorphism in intron 4 of the NOS3 gene. RESULTS: The wild type B allele was identified on 329 out of 392 chromosomes (frequency 0.84). The polymorphic A allele was present on 63 chromosomes (frequency 0.16). The genotype frequencies were as follows: 68% (B/B), 31% (A/B) and.5% (A/A). The distribution of genotype frequencies was significantly different between the study and control groups for allele A/B heterozygotes (NOS3(A/B)) (36.7 versus 23.8%, P = 0.03, OR 1.6, 95% CI 1.1--3.8). Only one individual was homozygous for the A allele (NOS3(A/A)). She was in the study group. Between women with primary and secondary recurrent miscarriages, no statistically significant difference between the distribution of NOS3(A/B) genotypes (28 versus 34%) was observed. CONCLUSIONS: These data support a role for the NOS3 gene as a genetic determinant of the risk of idiopathic recurrent miscarriage.