大鼠海马CA1区神经元高级可塑性（Metaplasticity）的研究

经验（experience）或突触活动依赖的突触信息传递效能的增强（LTP）或抑制（LTD）被称为突触可塑性（synaPticplasticity），是公认的学习和记忆的细胞分子学基础。突触可塑性的方向是突触信息传递效能的增强或降低；突触可塑性的程度是突触信息传递的效能增加量或降低量。突触活动历史可影响随后突触可塑性的方向或程度。这种突触可塑性的可塑性被称为高级可塑性（MetaP1asticity）。最明显的高级可塑性现象是发生在突触效能没有改变的情况下。经验或者突触活动可以同时诱导出突触可塑性和高级可塑性。除非知道突触活动的历史，否则很难预测突触可塑性的大小和方向。高级可塑性简单地讲就是过去的神经信息留下痕迹会对神经信息的加工处理产生持续性影响。目前高级可塑性的机理并不完全清楚。采用全细胞电压钳记录方法，在3周龄wistar大鼠海马脑片中，同时记录schaffer侧枝纤维一以1处兴奋性突触后膜电流（evokedEPsC）和自发性微小兴奋性突触后膜"电流（mEPSC）。结果显示，mEPSC和低频刺激诱导的长时程抑制（Long一TermDePre55ion，LTD）之间呈负相关，mEPsc的频率或幅值越小，诱导出的LTD幅度越大；应激和低钙溶液处理在降低记PsC的频率和幅值的同时并没有明显改变随后LTD的诱导幅，但是这两者负相关性依然存。相关系数在应激条件下有增加，在低钙溶液中有降低。以上结果提示，mPEsc的频率或幅值可能指示了过去的突触活动或经验产牛的高幼可朔件＿田、冲稀恻了喃层的，：。、云导的幅度。C鹉子妙触可黔和高级可黔中起着关键作。作为一种非选择性阳离子通道，van11101drec即tortyPel（VR1或TRPVI）在脑区中广泛表达，尤其在海马高表达。内源性配体可以激活该受体通道。但目前并不清楚vRI在海马突触可塑性当中的作用。我们发现VRI激动剂辣椒素不影响脑片中海马以1区基础突触传递，但是它阻断低频诱导（LFS，3Hz）的LTD，增强高频诱导（HFs，20OHz）的长时程增强（Long一TerlnPotetiantion，LTP）。也就是vRI激活改变了突触可塑性的方向，是一种经典的高级可塑性现象。正常情况下50Hz不能诱导出LTP，而加入辣椒素后易化了LTP的诱导。因此LTP诱导的闽值降低。辣椒素激动剂对突触可塑性或高级可塑性的效应不依赖协。A受体而依赖于H型钙调蛋白激酶（CaMKII）的调控。因为场。A受体电流和它的电流一电压曲线不受此激动剂影响，但CaMKII抑制剂KN-93或者VRI拮抗剂capsazepine却阻断了辣椒素的这种效应。这些发现，显示VRI可以调控海马以1区的高级突触可塑性，可能参与某些类型的学习和记忆。

应激对大鼠海马突触可塑性和学习记忆的影响

突触可塑性参与学习记忆，是学习记忆过程中必不可少的重要环节。应激能损伤或提高学习记忆、抑制长时程增强（Long一termPotentiation，LTP）、易化长时程抑制（Long一termdePressfon，LTD）。然而，应激经历依赖的长时程抑制（StressexperiencedePendentLTD，SLTD）在学习记忆中有什么意义还不清楚，这正是本文首先要探讨问题。其次，尽管我们在不同年龄时期的学习记忆能力不同，但是对所经历的重大应激事件仍然能产生牢固的记忆，这就有必要进一步通过阐明应激对突触可塑性的影响是否有年龄差异来解释SLTD的意义。再者，我们甚至不清楚为什么有的时候应激损伤学习记忆而有的时候又提高学习记忆。为了阐明这个问题，本文在最后一部分研究了哪些因素决定应激损伤还是提高学习记忆。为了探讨SLTD与学习记忆的关系，我们在第一部分实验中研究急性或亚急性的高台（ElevatedPlatform，EP）或足部电击（Footshock，Fs）对4周龄诚star大鼠海马CAI区LTD诱导的影响，以及这些应激条件对大鼠空间学习记忆的影响。结果显示：（l）急性EP易化LTD，亚急性EP不易化LTD；急性和亚急性FS都易化了LTD。（2）急性EP损伤空间记忆，亚急性EP对空间记忆没有影响；急性FS不影响空间记忆，亚急性FS却提高了空间记忆。这部分的实验结果表明：sLTD存在与否与应激对空间记忆的影响不是一一对应的关系，提示sLTD可能参与了应激记忆（对应激经历产生的记忆）。如果SLTD参与应激记忆，那么，研究应激对突触可塑性的影响是否有年龄依赖性将有助于解释不同年龄时期的学习记忆能力不同但是都能牢固记忆应激事件这一现象。为此，我们在第二部分实验中进一步研究EP对幼年、中年和老年动物（4，10和74周龄的Wistar大鼠）海马CAI区LTP／LTD诱导的影响。结果表明：（1）没有应激的情况下，LTP的大小随动物年龄的增加呈明显的倒U型关系，而低频刺激都不能诱导出LTD。（2）EP易化了这些年龄段大鼠的LTD，并完全阻断它们的LTP。值得注意的是，在三个年龄段大鼠中，EP易化的LTD大小一样。该部分实验结果提示：SLTD没有年龄依赖性，这与人和动物在不同年龄时期对所受到的重大应激事件都能产生牢固记忆这一现象相一致。所以，该部分结果进一步加强了第一部分结果的推测：SLTD参与应激记忆。应激有的时候提高动物的空间记忆能力，有的时候又损伤其空间记忆。为了阐明是什么因素决定应激损伤还是提高学习记忆，我们在第三部分实验中研究EP、FS和水迷宫游泳应激经历对六个年龄段动物（4，10，13，20，67，76周龄）在水迷宫任务中的影响。结果显示：（l）EP应激损伤无水迷宫游泳应激经历大鼠的空间记忆。（2）EP应激提高有游泳应激经历幼年大鼠的空间记忆；训练前外源性补充皮质酮或FS都抑制皮质酮或FS导致的空间记忆受损。（3）糖皮质激素受体的拮抗剂RU38486阻断上述的空间记忆成绩提高。所以，不同的应激经历和动物年龄两个因素共同决定了应激损伤还是提高学习记忆。

Ⅰ、新生期触觉刺激和短时间母婴分离经历对大鼠成年后学习记忆的影响 Ⅱ、银杏叶提取物对育亨宾所致大鼠空间工作记忆障碍的改善作用

本研究探讨了新生期的触觉刺激（tactile stimulation，TS）和母婴分离（maternal separation，MS）经历对大鼠成年后空间工作记忆和空间参考记忆的影响，以及对海马-前额叶神经通路的突触可塑性产生的效应。Wistar品系的母鼠分娩后，以split-litter方法对仔鼠进行分组：NTS组的仔鼠不接受触觉刺激和母婴分离；TS组的仔鼠在出生后第2-9天（postnatal day 2-9，PND2-9），或者PND10-17内，每天接受短暂（约30s）的人为抓握，并进行体表标记；TS/MS组的仔鼠在PND2-9，或者PND10-17内，接受TS组相同方式的抓握并在不同体表部位进行标记后，被单独地放入一个杯子中，杯中有取自鼠巢的垫料，每天与母鼠分离1h后返回鼠巢。按照常规方法饲养这些在新生期有不同经历的大鼠，待其成年后（3月龄），采用交互延缓作业（纠正错误法和不纠正错误法）、空间分辨作业及反转学习作业测试雄性大鼠的学习记忆功能，并观察多巴胺D1受体激动剂A77636对不同组成年雄鼠的工作记忆是否产生影响。采用活体电生理方法，高频刺激海马腹侧部在前额叶记录突触效能长时程增强（long-term potentiation，LTP），对PND2-9有不同经历的成年大鼠（雌雄兼用）的海马-前额叶LTP进行比较。 结果：（1）各组仔鼠间在PND30、PND60和PND90的体重都没有显著性差异，表明本研究中的新生期TS处理和MS处理不影响仔鼠的体重发育。 （2）在交互延缓作业-纠正错误法中，各组成年雄鼠在0s延缓期的达标天数没有显著性差异；0s延缓期达标后，再经过30天的训练，PND2-9TS组和PND10-17TS组的成年雄鼠达到的最长延缓期明显高于NTS组，而且在30s—50s延缓期内达标（正确率≥86.7%）的大鼠数量明显较多（与NTS组相比）。采用交互延缓作业-不纠正错误法，各组成年雄鼠在0s延缓期的训练成绩没有显著性差异，但是，PND2-9TS组和PND10-17TS组的成年雄鼠在40s延缓期的训练正确率明显高于NTS组，表明新生期的TS处理明显改善成年雄性大鼠成年后的空间工作记忆。 （3）各组成年雄鼠在空间分辨作业及反转学习作业中的成绩没有明显差异，表明新生期TS经历对雄鼠成年后空间学习记忆的影响是任务依赖性的：与前额叶有关的空间工作记忆功能比较容易受到新生期TS经历的影响，而空间参考记忆相对不容易受到新生期TS经历的影响。 （4）多巴胺D1受体激动剂A77636只有1个剂量（0.1mg/kg）对NTS组成年雄鼠的交互延缓作业成绩具有明显的改善效应。对PND2-9TS组成年雄鼠的交互延缓作业成绩，A77636的0.1mg/kg和1mg/kg剂量都具有明显改善效应。对PND10-17TS组成年雄鼠的交互延缓作业成绩，A77636的0.01mg/kg、0.1mg/kg和1mg/kg剂量都具有明显改善效应。与NTS组相比，A77636对这2个TS组成年雄性大鼠的有效改善剂量范围较宽，提示新生期TS处理经历对雄性大鼠成年后空间工作记忆的改善效应与其前额叶的多巴胺D1受体功能上调有关。 （5）与NTS组相比，PND2-9TS组雄性和雌性成年大鼠的海马-前额叶神经通路的LTP幅度都明显增加。由于海马-前额叶神经通路在空间工作记忆功能中起重要作用，新生期TS经历增强大鼠成年后的海马-前额叶神经通路的突触可塑性，为新生期TS经历增强大鼠成年后的空间工作记忆提供了电生理学的证据。TS成年大鼠海马-前额叶LTP增强可能与其前额叶的D1受体功能上调有关。 （6）本研究中，TS/MS组的新生期仔鼠在PND2-9或者PND10-17内，除了接受与TS组相同方式的抓握并在不同部位标记外，每天与母鼠分离1h，因此通过不同日龄段的TS/MS组与TS组的比较，拟对新生期MS处理的效应进行评估。结果发现，无论是对成年雄性大鼠的各项行为测试（空间分辨作业、交互延缓作业、A77636影响交互延缓作业的量效曲线），还是对成年雌性大鼠的行为测试（明/暗箱作业、一次性被动回避反应，论文Ⅱ），或者对海马-前额叶神经通路的LTP，新生期的MS处理对本研究中的所有测试指标在统计上都没有显著性的差异，说明新生期每天1h的母婴分离经历对大鼠成年后的学习记忆等行为及前额叶突触可塑性没有产生明显的影响，对前额叶D1受体功能也没有明显影响。 （7）对所有测试指标，本研究采用的2个仔鼠日龄段PND2-9和PND10-17之间的统计比较没有明显差异，提示PND2-9和PND10-17甚至整个泌乳期都是仔鼠神经系统对外界环境刺激比较敏感的发育关键期。 结论：新生期的触觉刺激经历改善雄性大鼠成年后的空间工作记忆，增强海马-前额叶神经通路的突触可塑性和前额叶D1受体功能；新生期短时间的母婴分离经历对大鼠成年后的空间工作记忆和前额叶突触可塑性等没有产生明显的影响，可能具有一定的生物学适应意义。

1. 大鼠海马-前额叶回路在学习记忆中的作用2. 芬克罗酮改善恒河猴空间工作记忆的谷氨酸机制

一、大鼠海马-前额叶回路在学习记忆中的作用 解剖学研究证实大鼠和猴的海马结构（hippocampal formation, HF；本文‘海马 (hippocampus, Hip)’一词即指海马结构）和前额叶 (prefrontal cortex, PFC) 之间存在一条单向、同侧和单突触的神经回路，即海马-前额叶回路（Hip-PFC回路）。Hip和PFC均参与学习记忆等多种认知功能，PFC是工作记忆的关键脑区，而Hip是空间参考记忆的关键脑区。虽然人们已经对PFC和Hip进行了广泛深入的研究，但对Hip-PFC回路参与哪些认知功能还知之甚少。本研究的目的就是通过暂时阻断Hip-PFC回路，探讨其在学习和记忆中的作用。 在大鼠，Hip-PFC回路中的纤维主要从Hip腹部 (ventral hippocampus, VH)发出，投射到PFC的前边缘皮质(prelimbic cortex, PLC)、下边缘皮质 (infralimbic cortex, ILC) 和外侧前额叶 (lateral prefrontal cortex) 等亚区，其中PLC是Hip-PFC主要投射的区域。我们通过给动物安装慢性导管向脑内注射GABAA受体激动剂muscimol (MU) 阻断Hip-PFC回路。注射位点包括 ①双侧PLC，②双侧VH，③一侧VH和对侧PLC (VH-PLC)。我们首先观察了在PLC或VH局部注射MU对自由活动大鼠PLC和VH脑电功率的影响，并以此确定在行为实验中所用蝇蕈醇的剂量。然后采用T-迷宫空间交互延缓作业 (spatial delayed alternation task) 测试Hip-PFC回路被阻断的动物的空间工作记忆功能；采用被动回避作业 (passive avoidance task) 测试其情绪相关记忆的能力（训练前给药；24 h后重测试）；采用Morris水迷宫作业 (Morris water maze task) 测试其空间参考记忆的能力（每天训练前给药；训练期（3 d）结束24 h后重测试）。结果表明：在大鼠PLC或VH局部注射0.5 μg/0.25μl MU后30 min显著抑制VH 和PLC的脑电功率 (VH, p < 0.01; PLC, p < 0.05 vs. PBS/baseline)。注射MU (0.5 μg/0.25μl) 到 ①双侧PLC、②双侧VH、③VH-PLC均显著降低动物在空间交互延缓作业 (All p < 0.001, vs. PBS) 和空间Morris水迷宫作业中的成绩 (All p < 0.05, vs. PBS)，表明Hip-PFC回路在空间工作记忆（空间短时记忆）和在空间参考记忆（空间长时记忆）中均起重要作用。在空间交互延缓作业中，双侧PLC被抑制的大鼠的成绩显著低于双侧VH或VH-PLC被抑制的动物，说明PFC在空间工作记忆功能中占有主导地位。在被动回避作业中，双侧VH被抑制动物的回避反应的潜伏期显著短于对照动物 (p < 0.05 vs. PBS)，说明双侧VH被抑制动物的情绪记忆受损；而双侧PLC或VH-PLC被抑制的动物其回避反应的潜伏期与对照动物无显著差异 (PLC, p > 0.9; VH-PLC, p > 0.3 vs. PBS)，表明双侧PLC或VH-PLC被抑制的动物情绪记忆正常。被动回避作业的结果说明VH参与情绪记忆的形成，但Hip-PFC回路在情绪记忆形成中不起重要作用。 以上结果表明，大鼠Hip-PFC回路参与空间工作记忆和空间参考记忆而不是情绪记忆功能。情绪记忆的关键脑结构是杏仁复合体 (amygdala complex, AMC)，VH与AMC有密切的纤维联系。VH被抑制的大鼠情绪记忆受损，说明情绪记忆可能与AMC-Hip回路有关。情绪记忆与空间记忆（参考记忆和工作记忆）在解剖上的分离说明，对于不同类型的记忆来说，其在脑内的信息加工过程是并行的。神经回路内部的信息加工过程则是串行的，回路上任何一个结构的破坏均可导致回路功能的损伤。本研究的结果为学习记忆的“多重记忆系统”理论和记忆信息加工的串行并行机制提供了新的实验证据。 二、芬克罗酮改善成年恒河猴空间工作记忆的谷氨酸机制 芬克罗酮是中科院昆明植物所郝小江等合成的取代吡咯烷酮类化合物。中科院昆明动物所蔡景霞等发现芬克罗酮能改善东莨菪碱、育亨宾等导致的多种动物的不同类型的学习记忆障碍，提高老年动物的学习记忆能力，尤其是老年猴的空间工作记忆。已证实芬克罗酮为部分钙激动剂，可使脑缺血沙土鼠脑内升高的谷氨酸降低，而使正常的沙土鼠海马胞外谷氨酸释放增加。那么芬克罗酮能否提高正常动物的学习记忆，其对正常动物学习记忆的提高是否与其增加谷氨酸的释放有关？本研究采用空间延缓反应作业和谷氨酸NMDA受体拮抗剂MK-801在正常成年猴恒河猴上探讨了以上问题。 结果表明，口服芬克罗酮可显著提高成年猴的空间工作记忆，其量效曲线呈倒‘U’形，符合许多促智药的量效特点。0.25 mg/kg和0.5 mg/kg为芬克罗酮的最佳有效剂量 (p < 0.05 vs. 安慰剂)。肌注MK-801 (0.1 mg/kg) 显著降低成年猴的空间工作记忆 (p < 0.01 vs. 安慰剂)，而口服2.0 mg/kg和4.0 mg/kg的芬克罗酮则显著改善MK-801导致的工作记忆障碍 (p < 0.05 vs. MK-801)。芬克罗酮的所有测试剂量不影响猴在作业中的反应时 (p > 0.05 vs. 安慰剂)，表明芬克罗酮在该剂量范围不影响动物的运动能力。 本研究结果提示，芬克罗酮可能通钙激动作用促进谷氨酸的释放，在一定剂量范围内提高胞外谷氨酸水平，提高正常动物的空间工作记忆等认知功能。 关键词：芬克罗酮，恒河猴，空间工作记忆，空间延缓反应作业，谷氨酸，MK-801

Effects of Naotan Pill on repair of neural cells and cognitive disorders in juvenile rats following hypoxia and ischemia

BACKGROUND: Hypoxia and ischemia induce neuronal damage, decreased neuronal numbers and synaptophysin levels, and deficits in learning and memory functions. Previous studies have shown that lycium barbarum polysaccharide, the most effective component of barbary wolfberry fruit, has protective effects on neural cells in hypoxia-ischemia. OBJECTIVE: To investigate the effects of Naotan Pill on glutamate-treated neural cells and on cognitive function in juvenile rats following hypoxia-ischemia. DESIGN, TIME AND SETTING: The randomized, controlled, in vivo study was performed at the Cell Laboratory of Lanzhou University, Lanzhou Institute of Modern Physics of Chinese Academy of Sciences, and Department of Traditional Chinese Medicine of Gansu Provincial Rehabilitation Center Hospital, China from December 2005 to August 2006. The cellular neurobiology, in vitro experiment was conducted at the Institute of Human Anatomy, Histology, Embryology and Neuroscience, School of Basic Medical Sciences, Lanzhou University, and Department of Traditional Chinese Medicine of Gansu Provincial Rehabilitation Center Hospital, China from March 2007 to January 2008. MATERIALS: Naotan Pill, composed of barbary wolfberry fruit, danshen root, grassleaf sweetflag rhizome, and glossy privet fruit, was prepared by Gansu Provincial Rehabilitation Center, China. Rabbit anti-synaptophysin, choline acetyl transferase polyclonal antibody, streptavidin-biotin complex kit and diaminobenzidine kit (Boster, Wuhan, China), as well as glutamate (Hualian, Shanghai, China) were used in this study. METHODS: Cortical neural cells were isolated from neonatal Wistar rats. Neural cell damage models were induced using glutamate, and administered Naotan Pill prior to and following damage. A total of 54 juvenile Wistar rats were equally and randomly assigned into model, Naotan Pill, and sham operation groups. The left common carotid artery was ligated, and then rat models of hypoxic-ischemic injury were assigned to the model and Naotan Pill groups. At 2 days following model induction, rats in the Naotan Pill group were administered Naotan Pill suspension for 21 days. In the model and sham operation groups, rats received an equal volume of saline. MAIN OUTCOME MEASURES: Neural cell morphology was observed using an inverted phase contrast microscope. Survival rate of neural cells was measured by MTT assay. Synaptophysin and choline acetyl transferase expression was observed in the hippocampal CA1 region of juvenile rats using immunohistochemistry. Cognitive function was tested by the Morris water maze. RESULTS: Pathological changes were detected in glutamate-treated neural cells. Neural cell morphology remained normal after Naotan Pill intervention. Absorbance and survival rate of neural cells were significantly greater following Naotan Pill intervention, compared to glutamate-treated neural cells (P < 0.05). Synaptophysin and choline acetyl transferase expression was lowest in the hippocampal CA1 region in the model group and highest in the sham operation group. Significant differences among groups were observed (P < 0.05). Escape latency and swimming distance were significantly longer in the model group compared to the Naotan Pill group (P < 0.05). CONCLUSION: Naotan Pill exhibited protective and repair effects on glutamate-treated neural cells. Naotan Pill upregulated synaptophysin and choline acetyl transferase expression in the hippocampus and improved cognitive function in rats following hypoxia-ischemia.

Toxicological effects of cinnabar in rats by NMR-based metabolic profiling of urine and serum

Cinnabar, an important traditional Chinese mineral medicine, has been widely used as a Chinese patent medicine ingredient for sedative therapy. However, the pharmaceutical and toxicological effects of cinnabar, especially in the whole organism, were subjected to few investigations. In this study, an NMR-based metabolomics approach has been applied to investigate the toxicological effects of cinnabar after intragastrical administration (dosed at 0.5, 2 and 5 g/kg body weight) on male Wistar rats.

Metabolic profiling studies on the toxicological effects of realgar in rats by H-1 NMR spectroscopy

The toxicological effects of realgar after intragastrical administration (1 g/kg body weight) were investigated over a 21 day period in male Wistar rats using metabonomic analysis of H-1 NMR spectra of urine, serum and liver tissue aqueous extracts. Liver and kidney histopathology examination and serum clinical chemistry analyses were also performed. H-1 NMR spectra and pattern recognition analyses from realgar treated animals showed increased excretion of urinary Kreb's cycle intermediates, increased levels of ketone bodies in urine and serum, and decreased levels of hepatic glucose and glycogen, as well as hypoglycemia and hyperlipoidemia, suggesting the Perturbation of energy metabolism. Elevated levels of choline containing metabolites and betaine in serum and liver tissue aqueous extracts and increased serum creatine indicated altered transmethylation. Decreased urinary levels of trimethylamine-N-oxide, phenylacetylglycine and hippurate suggested the effects on the gut microflora environment by realgar.

Mn(II)-monosubstituted polyoxometalates as candidates for contrast agents in magnetic resonance imaging

Two mono-substituted manganese polyoxometalates, K6MnSiW11O39 (MnSiW11) and K8MnP2W17O61 (MnP2W17), have been evaluated by in vivo and in vitro experiments as the candidates of potential tissue-specific contrast agents for magnetic resonance imaging (MRI). T-1-relaxivities of 12.1 mM(-1) s(-1) for MnSiW11 and 4.7 mM(-1) s(-1) for MnP2W17 (400 MHz, 25 degrees C) were higher than or similar to that of the commercial MRI contrast agent (GdDTPA). Their relaxivities in BSA and hTf solutions were also reported. After administration of MnSiW11 and MnP2W17 to Wistar rats, MR imaging showed longer and remarkable enhancement in rat liver and favorable renal excretion capability. The signal intensity increased by 74.0 +/- 4.9% for the liver during the whole imaging period (90 min) and by 67.2 +/- 5.3% for kidney within 20-70 min after injection at 40 +/- 3 mu mol kg(-1) dose for MnSiW11. MnP2W17 induced 71.5 +/- 15.1%. enhancement for the liver in 10-45 min range and 73.1 +/- 3.2% enhancement for kidney within 5-40 min after injection at 39 +/- 3 mu mol kg(-1) dose. In vitro and in vivo study showed MnSiW11 and MnP2W17 being favorable candidates as the tissue-specific contrast agents for MRI.

The gadolinium complexes with polyoxometalates as potential MRI contrast agents

The two gadolinium (Gd) polyoxometalates, K-15[Gd(BW11O39)(2)] [Gd(BW11)(2)] and K-17[Gd(CuW11O39)(2)] [Gd(CuW11)(2)] have been evaluated by in vivo and in vitro experiments as the candidates of potential tissue-specific magnetic resonance imaging (MRI) contrast agents. T-1 relaxivities of 17.12 mM(-1) . s(-1) for Gd(BW11)(2) and 19.95 mM(-1) . s(-1) for Gd(CuW11)(2) (400MHz, 25 degrees C) were much higher than that of the commercial MRI contrast agent (GdDTPA). Their relaxivities in bovine serum albumin and human serum transferrin solutions were also reported. After administration of Gd(BW11)(2) and Gd(CuW11)(2) to Wistar rats, MRI showed longer and remarkable enhancement in rat liver and favorable renal excretion capability. The signal intensity increased by 37.63 +/- 3.45% for the liver during the whole imaging period (100 min) and by 61.47 +/- 10.03% for kidney within 5-40 min after injection at 40 +/- 1-mu mol . kg(-1) dose for Gd(CuW11)(2), and Gd(BW11)(2) induced 50.44 +/- 3.51% enhancement in the liver in 5-50-min range and 61.47 +/- 10.03% enhancement for kidney within 5-40 min after injection at 39 +/- 4 mu mol . kg(-1) dose. In vitro and in vivo study showed that Gd(BW11)(2) and Gd(CuW11)(2) are favorable candidates as tissue-specific contrast agents for MRI.

NMR and pattern recognition studies on the acute biochemical effects of Lu(NO3)(3)

Pattern recognition methods were applied to the analysis of 600 MHz H-1 NMR spectra of urine from rats dosed with compounds that induced organ-specific damage in the liver and kidney. Male Wistar rats were separated into groups (n=4) and each was treated with one of following compounds: HgCl2, CCl4, Lu(NO3)(3) and Changle (a kind of rare earth complex mixed with La, Ce, Pr and Nd). Urine samples from the rats dosed with HgCl2, CCl4 and Lu(NO3)(3) were collected over a 24 h time course and the samples from the rats administrated with Changle were gained after 3 months. These samples were measured by 600 MHz NMR spectroscopy. Each spectrum was data-processed to provide 223 intensity-related descriptors of spectra. Urine spectral data corresponding to the time intervals, 0-8 h (HgCl2 and CCl4), 4-8 (Lu(NO3)(3)) h and 90 d (Changle) were analyzed using principal component analysis (PCA). Successful classification of the toxicity and biochemical effects of Lu(NO3)(3) was achieved.

胆总管探查后内置可降解支架并行Ⅰ期缝合的研究

目的　探讨胆总管 (CBD)探查后内置可降解支架并行Ⅰ期缝合在动物实验中的可行性和临床应用价值。方法　用 160只Wistar大鼠模拟CBD探查术 ,将其随机分为两组 :Ⅰ期缝合组 (对照组 ) ,内置可降解支架后行Ⅰ期缝合组 (实验组 )。观察手术前后大鼠碱性磷酸酶 (ALP)、体重、CBD外径的变化 ;记录缝合时间和总手术时间 ;术后观察胆漏的发生率、支架降解情况 ,并取肝组织做病理学检查。结果　两组在缝合时间、总手术时间及胆漏的发生率上差异无显著性 (P >0 .0 5 ) ;术后第 5周时内支架完全降解 ;对照组术后ALP持续性增高 ,实验组术后ALP一过性增高 ;实验组术后体重较对照组明显增加 ;对照组术后CBD较实验组明显扩张 ;对照组术后肝损伤的发生率 (8/15 )显著高于实验组 (1/15 )。结论　CBD探查后内置可降解支架并行Ⅰ期缝合的方法在动物实验中是较为安全有效的。

Comparison of biochemical effects induced by Changle between male and female rats using NMR and ICP-MS techniques

Metabolic profiles caused by rare earth complex were investigated using NMR and ICP-MS techniques. Male and female Wistar rats were treated orally with Changle (A kind of rare earth complex applied in agriculture to raise the production of crops) at dose of 2, 5 and 20 mg (.) kg(-1) body weight/day respectively for 90 d. Urine and serum samples are collected on 90 d. The relative concentrations of important endogenous metabolites in urine and serum are determined from H-1 NMR spectra and the contents of the four rare earth elements ( La, Ce, Pr and Nd) constituting Changle in the serum samples are measured by ICP-MS technique. Changle-induced renal and liver damage in rats is found based on the increase in the amounts of the amino acids, trimethylamine N-oxide, N, N-dimethyglycine, dimethylamine, succinate, aketoglutarate and ethanol as well as rare earth concentrations. The similarities and differentiations are found in the alteration patterns of metabolites and rare earth concentrations in serum.

Investigation on acute biochemical effects of Ce(NO3)(3) on liver and kidney tissues by MAS H-1 NMR spectroscopic-based metabonontic approach

High resolution magic angle spinning (MAS)-H-1 nuclear magnetic resonance (NMR) spectroscopic-based metabonomic approach was applied to the investigation on the acute biochemical effects of Ce(No-3)(3). Male Wistar rats were administrated with various doses of Ce (NO3)(3)(2, 10, and 50 mg(.)kg(-1) body weight), and MAS H-1 NMR spectra of intact liver and kidney tissues were analyzed using principal component analysis to extract toxicity information. The biochemical effects of Ce (NO3)(3) were characterized by the increase of triglycerides and lactate and the decrease of glycogen in rat liver tissue, together with an elevation of the triglyceride level and a depletion of glycerophosphocholine and betaine in kidney tissues. The target lesions of Ce (NO3)(3) on liver and kidney were found by MAS NMR-based metabonomic method. This study demonstrates that the combination of MAS H-1 NMR and pattern recognition analysis can be an effective method for studies of biochemical effects of rare earths.

Evaluation of bioeffects of a long-term administering ChangLe on rat by proton NMR method and biochemical examination

High resolution H-1 nuclear magnetic resonance ( NMR) spectroscopy has been employed to assess long-term toxicological effects of ChangLe (a kind of rare earth complex applied in agriculture). Male Wistar rats were administrated orally with ChangLe at doses of 0, 0.1, 0.2, 2.0, 10 and 20 mg/kg body weight daily, respectively, for 6 months. Urine was collected at-day 30, 60, go and serum samples were taken after 6 months. Many low-molecular weight metabolites were identified by H-1 NMR spectra of rat urine. A decrease in citrate and an increase in ketone bodies, creatinine, DMA, DMG, TMAO, and taurine in the urine of the rats. receiving high doses were found by H-1 NMR spectra. These may mean that high-dosage of ChangLe impairs the specific region of liver and kidney, such as renal tubule and mitochondria. The decrease in citrate and the increase in succinate and alpha-ketoglutarate were attributed to a combination of the inhibition of certain citric acid enzymes, renal tubular acidosis and the abnormal fatty acid catabolism. The information of the renal capillary necrosis could be derived from the increase in DMIA, DMG and TMAO. The increase in taurine was due to hepatic mitochondria dysfunction. The conclusions were supported by the results of biochemical measure. merits and enzymatic assay.

混合稀土对大鼠肝脏中7种酶的小剂量刺激作用

研究了常乐(用于肥料添加剂的一种混合稀土硝酸盐)对Wistar大鼠肝脏中7种常见酶(ALT,ICD,AST,LAP,ALP,γGT ,CHE)活性的变化,并用电感耦合等离子体质谱(ICP MS)测定了稀土在肝脏中的累积情况。结果表明,稀土对多种酶表现出低剂量激活、高剂量抑制的小剂量刺激作用 (Hormesis),但产生刺激作用的剂量随酶的种类不同而不同 ,并表现出明显的性别差异