不同剂量链尿佐菌素诱导2型糖尿病大鼠模型的研究

目的:探讨不同剂量链脲佐菌素(Streptozotocin,STZ)联合高糖高脂饮食对2型糖尿病大鼠模型建立的影响。方法:90只8周龄SD雄性大鼠随机平均分为六组:普通饲料喂养+缓冲液组、高糖高脂饲料喂养+缓冲液(H.E组)、高糖高脂饲料喂养+35mg/kg链尿佐菌素组(H.E+35 mg/kg STZ组)、高糖高脂饲料喂养+45 mg/kg链尿佐菌素组(H.E+45 mg/kg STZ组)、高糖高脂饲料喂养+55 mg/kg链尿佐菌素组(H.E+55 mg/kg STZ组)及高糖高脂饲料喂养+65 mg/kg链尿佐菌素组(H.E+65 mg/kg STZ组),高糖高脂饲料喂养4周后诱导胰岛素抵抗,继之腹腔注射STZ,建立2型糖尿病大鼠模型。检测体重、胰岛素、空腹血糖、血脂、胰岛素敏感指数(ISI)。结果:与常规饮食组相比,高糖高脂饮食各组大鼠出现空腹血浆胰岛素(FINS)、空腹血糖(FBG)、血清甘油三脂(TG)、总胆固醇(TC)、游离脂肪酸(FFA)显著升高(P0.01),ISI显著下降(P0.01)。不同剂量STZ注射,H.E+45 mg/kg STZ组成模率最高且无自愈现象。结论:通过STZ腹腔注射联合高糖高脂饮食可成功复制出实验性2型糖尿病动物模型,45 mg/kg为STZ理想注射剂量。     

链脲佐菌素诱导糖尿病小鼠模型的构建

目的:探讨建立理想糖尿病动物模型的方法。方法:A组采用空腹腹腔一次性注射65mg/kg1%链脲佐菌素(STZ)溶液的方法;B组采用空腹腹腔连续五天注射45mg/kg1%STZ溶液的方法,建立KM小鼠糖尿病模型。结果:建模1周后测血糖,A组平均血糖浓度为16.2mmol/L,死亡率为15%,成模率为55%;B组平均血糖浓度为20.2mmol/L,死亡率为20%,成模率为80%。持续观察一个月,A组血糖值始终在建模初期血糖水平上微弱波动,平均血糖浓度为14.4mmol/L,B组平均血糖浓度一个月后上升至24.8mmol/L,皆未见到复转。结论:采用空腹腹腔一次性注射65mg/kgSTZ溶液的方法复制出糖尿病模型,造模方法简便、用药量小,但成模率较低,血糖水平稳定性较弱;采用空腹腹腔连续五天注射45mg/kgSTZ溶液的方法复制出糖尿病模型,血糖浓度维持在较高水平,成模率高,死亡率较低,可应用于糖尿病及其并发症研究的各个领域。     

链脲佐菌素诱导C57小鼠1型糖尿病模型的研究

目的:通过小剂量多次腹腔注射链脲佐菌素(STZ)诱导建立与人类1型糖尿病相似的C57小鼠糖尿病模型,研究建模剂量和成模率。方法:将32只C57小鼠随机分为正常对照组(A)和实验组(B)。实验组(B)可分为低、中、高剂量组(50 mg/kg、70mg/kg、90 mg/kg)(n=8)。两组都喂普通饲料1周后,B组连续5天腹腔注射不同剂量STZ,测定注射前、注射后1周、2周、3周、4周、5周的空腹血糖和体重,观察小鼠饮食、饮水和排尿情况。STZ注射第3周进行口服糖耐量实验(OGTT)。结果:给药前A、B组体重和血糖无显著差异,给药1周后,B组饮水量和进食量明显增加,体重减轻。C57小鼠用药2周后,中剂量组达到建模标准,成模率75%。各剂量组均出现了糖耐量异常。结论:诱导建立C57小鼠1型糖尿病模型方法是连续5日腹腔注注射STZ,适宜剂量为70 mg/kg。     

高脂喂养合并小剂量链脲佐菌素建立2型糖尿病大鼠模型

目的 观察不同配方的高脂饲料,以及不同周龄的大鼠对于该模型的造模成功率和模型病变特点的影响.方法 将26只3周龄SD大鼠分为正常一组(N1组)、模型一组(M1组)和模型二组(M2组);26只5周龄SD大鼠分为正常二组(N2组)、模型三组(M3组)和模型四组(M4组).M1组和M3组给予高脂饲料配方一喂养,M2组和M4组给予高脂饲料配方二喂养.4周后,各模型组大鼠腹腔注射STZ溶液35 mg/kg.连续观察大鼠的空腹血糖(FBG)、空腹胰岛素(FIN)、总胆固醇(TG)、甘油三酯(TC)水平.结果 5周龄SD大鼠的FBG水平在注射STZ后两周即可达到稳定状态,并维持在较高的水平;高脂饲料配方二使大鼠的进食量和体重增加明显,并且成功诱导出胰岛素抵抗( insulin resistance,IR).结论 选取5周龄SD大鼠作为模型动物,并给予配方二高脂饲料喂养,所建立的大鼠模型具备2型糖尿病的主要特征,是值得推广的2型糖尿病动物模型.     

秋茄枝乙醇提取物减轻链脲佐菌素诱导的大鼠肝脏和胰腺病理损伤

目的:研究秋茄枝乙醇提取物(EEK)对链脲佐菌素(STZ)诱导的2型糖尿病(T2DM)大鼠肝脏和胰腺组织病理结构的影响。方法:以高脂饲料喂养联合STZ建立T2DM大鼠模型。大鼠分为为正常对照组、T2DM模型组、二甲双胍组、EEK低、中、高剂量组。大鼠给药4周后处死,取肝脏和胰腺进行组织病理学检查。结果:随着EEK剂量的增加,大鼠肝脏和胰岛组织的病理损伤逐步减轻。结论:EEK有助于修复STZ诱导的T2DM大鼠受损的肝脏和胰岛组织。     

链脲佐菌素诱导糖尿病肺纤维化小鼠模型的建立与评价

目的 探究链脲佐菌素(streptozotocin, STZ)诱导糖尿病肺纤维化(diabetic pulmonary fibrosis, DPF)小鼠模型的建立方法,为临床研究提供稳定的DPF动物模型。方法 将60只雄性C57BL/6小鼠随机分为3组：正常对照组(NG,n=20)、糖尿病肺纤维化1组(DPF1,n=20)、糖尿病肺纤维化2组(DPF2,n=20)。隔夜禁食不禁水后测定小鼠空腹血糖和体重,随后DPF1组一次性腹腔注射大剂量STZ(150 mg/kg),DPF2组连续5 d每天腹腔注射小剂量STZ(50 mg/kg),NG组腹腔注射等量无菌柠檬酸盐缓冲液。注射完毕后,每天观察小鼠的一般情况,每周测定小鼠体重和随机血糖(random blood glucose, RBG),正常喂养16周,每4周每组随机选取5只小鼠处死取材,行病理和分子生物学检测,评估小鼠肺纤维化的程度。结果 STZ诱导后,DPF1组和DPF2组均出现“多饮、多尿、多食、体重减轻(三多一少)”的典型糖尿病症状。DPF1组和DPF2组诱导后体重增加均显著低于NG组,并于第8周后缓慢减轻(P<0.05);...     

高脂饮食联合链脲佐菌素建立2型糖尿病大鼠模型的研究进展

2型糖尿病大鼠模型的建立能够为糖尿病及其并发症的发病机制、预防、诊断及治疗的研究提供理想的动物实验技术平台。2型糖尿病大鼠模型的成模率受多种因素的影响,本文就建立2型糖尿病大鼠模型的主要影响因素STZ的应用、高脂高糖饮食及大鼠的选择与饲养等做一综述。以期对建立2型糖尿病大鼠模型的方法提供一定的参考价值。     

链脲佐菌素诱导长爪沙鼠Ⅰ型糖尿病模型的实验研究

目的探讨链脲佐菌素(STZ)诱导长爪沙鼠Ⅰ型糖尿病模型的可能性,并观察模型动物早期肾脏损害情况。方法雄性长爪沙鼠96只,随机分为正常对照组(NC组)、模型组1(DM1组)、模型组2(DM2组),DM1及DM2组沙鼠分别一次性腹腔注射100 mg/kg、200 mg/kg STZ,NC组注射等量柠檬酸盐缓冲溶液。注射STZ后1、2、4、6周末,分别监测沙鼠一般情况,血糖、胰岛素等血清学指标和尿液指标,并处死沙鼠进行胰腺和肾脏组织的病理学检查。结果注射STZ 24 h后,DM2组及DM1组部分沙鼠逐渐出现典型的"三多一少"症状,随着病程的发展,DM2组沙鼠持续高血糖,DM1组沙鼠血糖值与NC组差异有显著性(P0.05),但有下降趋势;DM2组沙鼠胰岛素显著性降低(P0.05),其他血清学指标及尿液指标均显著性升高(P0.05),DM1组沙鼠各指标差异无显著性。DM2组沙鼠及DM1组少数沙鼠胰腺组织中可见胰岛β细胞减少、空泡样变性等变化,DM2组沙鼠肾脏组织中出现肾小球基质增多,毛细血管襻扩张等病变,DM1组沙鼠肾脏组织未见明显变化。结论 STZ 200 mg/kg可成功诱导长爪沙鼠Ⅰ型糖尿病模型,在病程早期沙鼠肾脏结构和功能已经发生改变。     

实验性链脲佐菌素诱导的大、小鼠糖尿病动物模型研究进展

糖尿病正呈快速上升趋势,而糖尿病的病因、发病机制尚未完全阐明,糖尿病及其并发症的预防和治疗仍不完善。因此,在糖尿病研究领域优化糖尿病实验动物模型的研究,寻找更接近人类糖尿病自然发病过程的动物模型,对于深入研究糖尿病具有重要的科学意义。     

四氧嘧啶与链脲佐菌素诱导兔1型糖尿病模型的比较

目的观察四氧嘧啶(alloxan,ALX)与链脲佐菌素(streptozotocin,STZ)诱导新西兰兔1型糖尿病模型的差异,探讨建模的最佳方法。方法 70只新西兰兔分为3组:实验组56只,又随机分为ALX和STZ两组,每组28只,采用两次给药,第一次剂量为100 mg/kg,48 h后第二次给药,剂量为120 mg/kg;对照组C组14只,相同方法给予等量生理盐水。每组给药后于不同时间监测空腹血糖、尿糖、尿酮、空腹体重、饮水量、排尿量、渗透压及电解质变化情况。结果一周后ALX组和STZ组成模率分别为71.43%和64.26%,死亡率分别为25%和17.86%,两组之间比较成模率及死亡率均无明显统计学差异(P0.05);两组之间血糖浓度差异有统计学意义(P0.05)。结论 ALX与STZ分两次给药均可诱导稳定的兔1型糖尿病模型,从成模率、死亡率及建模成本综合考虑,ALX是建立兔1型糖尿病模型的优先选择。     

Intestinal endotoxin in induction of type 1 diabetes

We studied serum level of intestinal flora endotoxin (LPS) in 45 children and adolescents aged 3-17 years old with diabetes mellitus type 1. Levels of endotoxin, were significantly elevated in type 1 diabetic patients (2.89 +/- 0.33 Eu/ml) compared with control (0.4 +/- 0.03 Eu/ml). There was significant difference in serum LPS levels in patients with type 1 diabetes onset (3.93 +/- 0.79 Eu/ml) compared with children and adolescent with old time diabetes (2.37 +/- 0.27 Eu/ml). These results have a major implication on our understanding of the role of gut flora endotoxin in pathogenesis of type 1 diabetes.     

Characterization of tree shrew telomeres and telomerase

The use of tree shrews as experimental animals for biomedical research is a new practice. Several recent studies suggest that tree shrews are suitable for studying cancers, including breast cancer, glioblastoma,lung cancer, and hepatocellular carcinoma. However, the telomeres and the telomerase of tree shrews have not been studied to date. Here, we characterize telomeres and telomerase in tree shrews. The telomere length of tree shrews is approximately 23 kb, which is longer than that of primates and shorter than that of mice, and it is extended in breast tumor tissues according to Southern blot and flow-fluorescence in situ hybridization(FISH) analyses. Tree shrew spleen, bone marrow, testis, ovary, and uterus show high telomerase activities, which are increased in breast tumor tissues by telomeric repeat amplification protocol assays. The telomere length becomes shorter, and telomerase activity decreases with age. The tree shrew TERT and TERC are more highly similar to primates than to rodents. These findings lay a solid foundation for using tree shrews to study aging and cancers.     

Spontaneous malignomas in Tupaia (tree shrew)

Nine spontaneous malignomas of the tree shrew were detected and analysed during an observation period of nine years. The tumours were histopathologically examined and classified. All malignomas developed in imported Tupaia only. From the tumour cells of two different animals new Tupaia herpesviruses were isolated. This is the first. report on spontaneous malignomas of Tupaia in captivity.     

树鼩Retn基因的克隆及序列测定

目的 克隆树鼩(Tupaia belangeri)Retn基因,为在树鼩中开展Retn相关研究提供实验资料.方法 在树鼩脂肪组织中抽提总RNA,用RT-PCR进行基因扩增,通过基因克隆、重组质粒的酶切鉴定,对Retn克隆质粒的序列测定和分析.结果 抽提的总RNA完整性较好,RT-PCR产物电泳检测得到了目的条带,重组克...     

慢性吗啡依赖树鼩模型的建立

吗啡是一种有效的镇痛药,但易使动物产生耐受性和成瘾性。在该实验中,中缅树鼩(Tupai a belangeri chinensis)连续7d,每天接受三次肌肉注射递增剂量(5、10、15、20mg/kg体重)吗啡后对吗啡产生耐受和依赖;吗啡注射完成后,腹腔注射纳洛酮(1.25mg/kg体重)催瘾,可诱导其条件性位置厌恶(conditioned place aversion,CPA)及相应吗啡戒断症状的出现。该结果提示树鼩慢性吗啡依赖模型的建立可用于研究吗啡依赖和耐受的生物学机制,以及减轻戒断症状药物的筛选。     

Rhombomere-specific patterns of apoptosis in the tree shrew Tupaia belangeri

Whether rhombomere-specific patterns of apoptosis exist in the developing hindbrain of vertebrates is under debate. We have investigated the sequence of apoptotic events in three-dimensionally reconstructed hindbrains of Tupaia belangeri (8- to 19-somite embryos). Apoptotic cells were identified by structural criteria and by applying an in situ tailing technique to visualize DNA fragmentation. Seven rhombomeres originated from three pro-rhombomeres. Among pre-migratory neural crest cells in the dorsal thirds of the neural folds, the earliest apoptotic concentrations appeared in the developing third rhombomere (r3). Dorsal apoptotic maxima then persisted in r3, extended from r3 to r2, and also arose in r5. Transverse apoptotic bands increased the total amount of apoptotic cells in odd-numbered rhombomeres first in r3 and, with a delay, also in r5. This sequence of apoptotic events was paralleled by an approximate rostrocaudal sequence of neural crest cell delamination from the even-numbered rhombomeres. Thus, large-scale apoptosis in r3 and r5 helped to establish crest-free zones that segregated streams of migrating neural crest cells adjacent to r2, r4, and r6. The sequence of apoptotic events observed in the dorsal thirds of rhombomeres matches that reported for the chick embryo. Other shared features are apoptotic peaks in the position of a circumscribed ventricular protrusion of fusing parts of the neural folds in r1 and r2, and Y-shaped apoptotic patterns composed of apoptotic maxima in the dorsal and lateral thirds of r1, r2, and r3. These rhombomere-specific patterns of apoptosis may therefore represent a conserved character, at least in amniotes.This work was supported by the Deutsche Forschungsgemeinschaft (KN 525/1–1, KN 525/1–2, BR 1185/4–1, and former Sonderforschungsbereich 89: Cardiology)