增塑剂邻苯二甲酸二丁酯致小鼠睾丸组织的病理学改变

背景：目前国内外研究邻苯二甲酸二丁酯对生殖损害研究对象多为大鼠,且不同时间点下小鼠病理组织学未见,以小鼠为移植对象没有明确移植时间。 目的：探讨邻苯二甲酸二丁酯致小鼠睾丸组织病理学改变,并找出其改变最大的时间点,为移植做准备。 方法：妊娠balb/c小鼠20只随机分成3组,分别为正常对照组6只,玉米油对照组6只,DBP组8只。自妊娠12~21 d,分别经口给予邻苯二甲酸二丁酯和玉米油,分别在小鼠出生后4~8周每间隔1周观察仔代雄小鼠睾丸的组织病理学改变,找到变化最大的时间点。 结果与结论：邻苯二甲酸二丁酯组染毒小鼠睾丸出现明显的生理、病理和电镜下的改变。邻苯二甲酸二丁酯可引起雄性仔鼠性分化异常,睾丸生精上皮损害和生精过程障碍,从而对雄性仔鼠生育力产生不利影响,在5,6周小鼠睾丸组织损害最大,可以作为移植变化最大时间进行选择。     

急性应激对大鼠脑内5-羟色胺1A受体mRNA表达的影响

目的 探讨急性应激对大鼠脑内5-羟色胺1A(5-HT1A)受体mRNA表达的影响。方法 将12只雄性Sprague-Dawley大鼠随机分为应激组和对照组,每组6只。根据5-HT1A受体互补DNA(eDNA)序列合成相应的特异性引物,用聚合酶链反应(PCR)法观察强迫游泳应激后3 h大鼠海马、下丘脑和中脑5-HT1A受体mRNA表达,并测定各脑区阳性电泳条带密度与β肌动蛋白(β-actin)密度的百分比。结果 应激后3 h,大鼠下丘脑5-HT1A受体mRNA表达相对水平为(64.3±6.7)％,显著低于对照组(78.9±8.7)％(t=3.263.P<0.05);海马、中脑5-HT1A受体mRNA表达相对水平分别为41.5％±7.1％、37.4％±5.6％,均分别显著低于对照组64.8％±9.6％、63.9％±6.3％(t分别为4.782、7.701,P均<0.01)。结论 急性应激后大鼠海马、下丘脑和中脑5-HT1A受体mRNA的表达降低。     

丙戊酸干预SH-SY5Y细胞的差异蛋白表达

实验采用双向荧光差异凝胶电泳法发现了丙戊酸处理SH-SY5Y细胞有3种差异蛋白表达,这3种蛋白均与细胞内氧化应激有关,其中真核翻译起始因子4A亚基1蛋白和三磷酸腺苷6V亚基1B2亚单位蛋白表达下调,而核内不均一性核糖核蛋白K表达上调。进一步采用基质-辅助激光解析/电离-飞行时间质谱以及蛋白免疫印迹方法鉴定并验证了其中1种蛋白--真核翻译起始因子4A亚基1。说明丙戊酸可通过调节真核翻译起始因子4A亚基1蛋白的表达来进行抗氧化作用。     

大鼠脊髓内5-HT2C,5-HT3,5-HT6和5-HT7受体亚型mRNAs的表达

目的:观察5-HT2C,5-HT3,5-HT6和5-HT7受体亚型mRNAs在大鼠脊髓不同节段的表达.方法:反转录PCR方法.结果:5-HT2C受体亚型mRNA在颈、胸、腰、骶段脊髓的背角(DH)和前角(VH)均有较强的表达;5-HT3受体mRNA在各节段脊髓DH的表达水平较高,而在VH则较低;与5-HT3受体亚型相反,5-HT6受体亚型mR-NA在脊髓VH的表达水平高于DH;5-HT7受体mRNA在脊髓的表达则与5-HT3受体相似,在各节段的DH均有较高水平的表达.不同的受体亚型在脊髓同一节段以及同一受体亚型在不同脊髓节段的表达水平存在差异.结论:本研究结果表明,上述四种5-HT受体亚型在脊髓具有不同的表达特点,提示它们在脊髓水平可能发挥着不同的生理作用,并为深入探讨5-HT受体参与伤害性感受和运动的调节机制提供了依据.     

针刺后中缝大核生长抑素mRNA的表达及其与5—HT的共存

为探讨中缝大核（ｎｕｃｌｅｕｓｒａｐｈｅｓｍａｇｎｕｓ，ＲＭ）内生长抑素（ｓｏｍａｔｏｓｔａｉｎ，ＳＯＭ）在针刺镇痛中的作用，本文用原位杂交组织化学方法（ＩＳＨＨ）和免疫细胞化学（ＩＣ）相结合的双标重技术，观察了大鼠ＲＭ内ＳＯＭｍＲＮＡ的正常，疼痛刺激，单纯电针刺激和电针镇痛下的变化特点，结果发现：典型ＳＯＭｍＲＮＡ阳性细胞胞体及突起近端内含蓝紫色颗粒，胞核不着色呈突泡状，正常组ＲＭ内ＳＯＭｍＲＮ     

成年大鼠脑内5-HT能神经纤维向胎鼠脑皮层移植物内投射的研究

目的:探讨大鼠胎脑皮层组织同种移植后的存活情况,以及宿主脑组织与移植物之间是否能建立神经纤维联系.方法:移植受体(宿主)为正常雄性成年Wistar大鼠,移植供体取自胎龄15～17d的Wistar孕鼠.在移植手术后不同时间取脑切片,用ABC法进行免疫组织化学染色,显示5-HT能神经纤维及其在宿主脑内和移植物中的分布情况.结果:同种胎鼠脑皮层组织移植后存活率为30%,ABC法显示有5-HT能神经纤维从宿主脑组织长入移植物中.结论:同种胎脑皮层组织移植后移植物与宿主脑组织可以建立神经纤维联系.     

锂-匹罗卡品致癎大鼠认知功能与海马苔藓纤维发芽和5-HT表达的变化

目的探讨癫癎发作后海马结构和海马5-羟色胺(5-HT)水平的变化,以及与认知功能改变的关系。方法采用锂-匹罗卡品复制大鼠癫癎模型,观察大鼠癫癎发作后大鼠海马组织结构、海马组织中5-HT水平的变化,并用Morris水迷宫观察大鼠认知功能的改变。结果 (1)大鼠癫癎发作后海马Timms染色显示苔藓纤维发芽(MFS)明显,半定量评分显示评分明显增高;(2)癫癎发作后海马5-HT免疫组织化学染色显示海马组织中5-HT神经元数量以及5-HT水平均明显减少;(3)癫癎发作后大鼠认知功能明显受到影响,大鼠寻找目标的潜伏期明显延长、游泳轨迹发生明显变化,以及规定时间内穿越平台次数减少。结论大鼠癫癎发作后认知功能明显下降,其原因可能与海马5-HT神经元数量以及5-HT水平的减少有关;癫癎的发作可能与海马苔藓纤维发芽有关。     

Drebrins和Icam-5在Fmr-1基因敲除鼠大脑皮层的表达和意义

目的 观察脆性X综合征(FXS)模型小鼠不同发育时期大脑皮层中Drebrin A、Drebrin E及Icam-5 mRNA水平变化情况及意义.方法 应用荧光实时定量PCR(RT-PCR)法检测FmrJ基因敲除KO小鼠及野生健康对照小鼠H出生后第7天、第14天、第21天和第28天大脑皮层Drebrin A、Drebrin E及Icam-5 mRNA的表达(4≤n≤10).结果 KO组小鼠出生后第14天Drebrin A mRNA水平较健康对照组小鼠明显降低,而同时间Drebrin E mRNA水平较健康对照组小鼠明显增高,差异均有统计学意义(P＜0.05);KO组小鼠Icam-5 mRNA水平在出生后第14和21天均明显高于健康对照组,差异均有统计学意义(P＜0.05).结论 Drebrin A和Drebrin E在大脑皮层发育期的表达交替延迟及Icam-5的一过性过度表达是FXS智力低下的原因之一.     

孕期酒精暴露对子代大鼠学习记忆及海马N-甲基-D-天冬氨酸受体2B亚基表达的影响

目的 研究孕期酒精暴露对子代大鼠学习记忆及海马N-甲基-D-天冬氨酸(NMDA)受体2B亚基(NR2B)表达的影响.方法 按照随机数字表法,将雌性SD大鼠随机分为正常对照组、饮酒对照组和孕期酒精暴露组,每组各8只;饮酒法建立大鼠孕期酒精暴露模型,子代成年后,采用Y-型迷宫测试子鼠学习记忆成绩;采用聚合酶链反应分析子鼠海马组织NR2B mRNA的表达;采用免疫荧光法检测子鼠海马区NR2B蛋白表达.结果 (1)各组子鼠成年后学习记忆成绩的差异有统计学意义(F=4.566,P＜0.05),孕期酒精暴露组子鼠学习记忆成绩[(43.00±15.33)次]比正常对照组[ (25.13±12.35)次]和饮酒对照组[(26.12±11.95)次]明显下降(P均＜0.05);(2)各组子鼠成年后海马组织中NR2B mRNA表达差异有统计学意义(F=29.795,P＜0.01),孕期酒精暴露组子鼠海马区NR2B mRNA表达(0.97±0.14)较正常对照组(0.52±0.10)和饮酒对照组(0.62±0.12)明显上升(P均＜0.01);孕期酒精暴露组子鼠海马区NR2B蛋白表达明显增加.结论 孕期酒精暴露对子代大鼠的神经损伤可能与NMDA受体亚基NR2B蛋白表达的上调有关.     

缺氧预处理对创伤性脑损伤大鼠 Claudin5 表达及血脑屏障通透性的影响

目的探讨缺氧预处理对创伤性脑损伤大鼠脑组织紧密连接蛋白Claudin-5的表达及血-脑屏障通透性的影响。方法204只大鼠随机分为创伤性脑损伤组（T组）96例,缺氧预处理后脑损伤组（H组）96例及对照组12例。T组行自由落体撞击法建立大鼠创伤性脑损伤模型,H组给予3d缺氧预处理后,同法致脑损伤,两组大鼠于伤后1h、4h、8h、12h、24h、3d、7d、14d断头处死。采用干湿重法测脑组织含水量：Real—timePCR和Westernblot检测各组大鼠挫伤区周围脑组织Claudin-5mRNA及蛋白表达变化;IgG法检测血一脑屏障通透性变化。结果T组和H组伤后1hClaudin-5mRNA及蛋白表达开始降低,8～12h降至最低点,1d开始上升,直至伤后14d渐趋于对照组水平;其中H组各时间点Claudin-5mRNA及蛋白表达均高于T组。T组各时间点血一脑屏障通透性及脑组织含水量均明显高于H组（P〈0．05）,且两组均高于对照组（P〈0．05）。结论缺氧预处理可在创伤性脑损伤早期上调紧密连接蛋白Claudin-5的表达,维持血-脑屏障完整性,减轻脑水肿。     

Elevation of fetal dopamine following exposure to methamphetamine in utero

The effect of methamphetamine on fetal dopaminergic function was examined following treatment of pregnant mice twice daily with 40 mg/kg methamphetamine from either gestational day (GD) 7-13 or from GD 7-15. Dopamine levels were elevated in fetal GD 16 corpus striatum and rostral mesencephalon following both treatment regimens. This increase in fetal dopamine is consistent with our findings that exposure to methamphetamine in utero results in adult dopaminergic neurons which are more responsive in terms of methamphetamine induced release of the neurotransmitter and more sensitive to the neurotoxic effects of the drug.     

Acute response of fetal rat telencephalon to ultrasound exposure in utero

Pregnant rats were exposed to ultrasound or microwaves from transducers located over one uterine horn. Ultrasound intensity (SPTA) was 0.78 W/cm2 for 30 min at a frequency of 2.5 MHz. Microwave exposure was used to reproduce approximately the rate of rise of uterine temperature of the rats exposed to ultrasound. The average peak temperature was 40.1 degrees C for ultrasound exposure and 42.2 degrees C for microwave exposure. On Gestational Day 16, 24 h after exposure, fetuses were removed and prepared for morphological examination of the developing cerebral cortical mantle. Morphometric measurements were made of nuclear area of subventricular zone cells, number of mitoses per mm in the ventricular zone, number of pyknotic cells in the mantle per mm, and number of ventricular macrophages per mm. Both exposures increased nuclear size and numbers of pyknotic cells and macrophages, and decreased the number of mitotic figures. The data from the four measurements were evidence of damage from ultrasound similar to the effects produced by microwave heating. The thermal effects of ultrasound, even at relatively low levels of rise in temperature, may have been the cause of the damage to the fetal cortex in these experiments or may have interacted with other effects of ultrasound energies to produce damage to developing neurons.     

Meningocele and ankyloblepharon following in utero exposure to olanzapine.

Although atypical antipsychotics are widely used during pregnancy, their safety is not well established. This case highlights the possible teratogenic effect of olanzapine, in which the baby was born with meningocele and ankyloblepharon. It is suggested that olanzapine may interfere with embryonic development at different stages of pregnancy.     

Differential expression of synaptosome-associated protein 25 kDa [SNAP-25] in hippocampi of neonatal mice following exposure to human influenza virus in utero

We investigated the role of maternal exposure to human influenza virus [HI] in C57BL/6 mice on day 9 of pregnancy on the hippocampal expression of SNAP-25 in postnatal day 0 neonates, and compared them to sham-infected pups. The expression of SNAP-25 in infected neonates varied along the septotemporal axis of hippocampus and in various anatomic layers. Quantitative densitometric analysis of specific immunogold silver-enhanced SNAP-25 immunoreactivity [IR] showed increases of 40–347% over control in all septal–dorsal hippocampal layers except for the subplate layer. In mid septo-temporal hippocampus, SNAP-25 IR increased by 10–114% over control in all layers, except for the hippocampal plate, but the extent of this increase was smaller than in the dorsal–septal area. Finally,in temporal–ventral levels, SNAP-25 expression was reduced in all infected layers by 21–33% below control except for mild increases of 8.8 and 10% in subplate and hippocampal plate layers. Additionally, the infected SNAP-25 maximal density bin shifted to lower values dorsally and to higher values medially, with ventral maximal bins remaining unchanged when compared to controls. The differential expression of SNAP-25 in the hippocampi of infected neonates indicates a variable degree of vulnerability across the septo-temporal axis of hippocampus. It is surmised that while viral infection may induce excitotoxicity in the ventral hippocampus, it may cause reactive synapto-genesis in the medial and dorsal sectors of the developing brains of postnatal day 0 neonates.     

Regional differences in cortical dendrite morphology following in utero exposure to cocaine

In utero exposure to cocaine has been shown to affect dopaminergic populations of developing neurons in the central nervous system (CNS). To determine if this was a regionally specific effect or the result of a global phenomenon, we used a Golgi-Cox analysis to measure several parameters of neuronal development in murine neurons from frontal cortex, a region of the cortex containing monoamine innervation, and somatosensory cortex, a monoamine sparse part of the cortex. Results of these analyses show that in utero exposure to cocaine affects total dendrite length in histotypical layers III and IV and dendritic volume in layer III of the frontal cortex. These effects are not present in the somatosensory cortex.     

Different effects by sex on hypothalamic-pituitary axis of prepubertal offspring rats produced by in utero and lactational exposure to di-(2-ethylhexyl) phthalate (DEHP)

This study investigated the effect of pre and perinatal exposure to di-(2-ethylhexyl) phthalate (DEHP) on the neuroendocrine parameters that regulate reproduction in prepubertal male and female rats. DEHP at doses of 3 and 30mg/kgbw/day was administered orally in the drinking water to dam rats since pregnancy onset until the moment of pups sacrifice at 15 days of age. In these animals gonadotropin serum level and the hypothalamic contents of the amino acids aspartate, glutamate and gamma-aminobutyric acid were determined. No changes in gonadotropin levels and amino acid neurotransmitters were detected at the low dose in both sexes. However, DEHP administered at high dose (30mg/kgbw/day) to dams produced a significant decrease in the inhibitory neurotransmitter GABA and an increase in the stimulatory neurotransmitter aspartate in prepubertal male offspring rats. These modifications were accompanied by gonadotropin serum levels increase. On the contrary, in treated female rats this chemical increased both, aspartate and GABA, which exert a characteristic stimulatory action on gonadotropin in 15-day-old normal females. This study provides new data about changes produced by DEHP on the hypothalamic amino acid neurotransmitters involved in the neuroendocrine reproductive regulation, in prepubertal male and female rat offspring from dams exposed during gestational and lactational periods. These alterations induced by DEHP exposure could be related to the gonadotropin modifications also described in this work, and with changes in the production of sexual hormones previously reported by other authors.     

Differential expression of GABA(A) receptor subunit mRNAs and ligand binding sites in rat brain following phencyclidine administration

Recent biochemical observations have suggested the abnormalities in the gamma-amino-butyric acid (GABA)ergic system in schizophrenic brains. In the present study, we investigated the subunits gene expressions and ligand binding of the GABA(A) receptor following acute and chronic administration of phencyclidine (PCP), which induces schizophrenia-like symptoms, in rats using in situ hybridization and in vitro quantitative autoradiography. PCP i.p. administration at a daily dose of 7.5 mg/kg resulted in a significant decrease in expression of alpha 1 subunit mRNA in cerebral cortices (cingulate (-13%) and temporal cortex (-6%)) and hippocampal formation (CA1 (-11%), CA2 (-10%), CA3 (-11%) and dentate gyrus (-12%)) 1 h after a single treatment. In the repeated PCP administrations for 14 days, the expression of beta 2 mRNA in the cerebellum (-10%) and of beta 3 mRNA in the cerebral cortices (cingulate (-12%), parietal (-16%) and temporal cortex (-16%), caudate putamen (-18%), inferior colliculus (-18%), and cerebellum (-15%) were significantly decreased. In addition, [(35)S]t-butylbicyclophosphorothionate (TBPS) binding was also reduced in layer IV of the frontoparietal cortex (-14%), inferior colliculus (-17%), and cerebellum (-12%) following chronic PCP treatment, while no changes were observed following acute PCP treatment. These results indicate that single and repeated administrations of PCP independently regulate the expression of GABA(A)/benzodiazepine (BZD) receptor subunits mRNA and its receptor binding in the brain.     

Synaptic density of caudate-putamen and visual cortex following exposure to ethanol in utero

Pregnant Long-Evans rats were fed a liquid diet containing ethanol (30% of total calories) during days 3–19 of gestation. Controls were given ad libitum access to liquid diet lacking ethanol, or pair-fed isocaloric amounts based on consumption by the animals in the ethanol group. Brain development of female offspring was evaluated by analysis of electron micrographs of caudate-putamen and visual cortex. Numbers of presynaptic terminals and synaptic junctions (synaptic density) per unit area were compared for 14- and 28-day-old offspring of dams from the three treatment groups. Synaptic density of the caudate-putamen and visual cortex was not affected by ethanol at 14 or 28 days. Although exposure to ethanol during a period comparable to the first two trimesters of human development with minimal or no undernutrition did not affect numerical density of synapses in visual cortex or caudateputamen, synaptogenesis of caudate-putamen was altered in offspring of pair-fed animals.