糖尿病大鼠心力衰竭时心肌细胞凋亡的研究

目的探讨糖尿病大鼠心力衰竭时是否存在心肌细胞凋亡.方法建立STZ糖尿病大鼠模型,饲养12周,经心功能检测后确认为糖尿病心力衰竭的大鼠,采用TUNEL法及TEM法,检测糖尿病大鼠左室心肌的凋亡细胞.结果 糖尿病大鼠出现心功能异常并可见凋亡的心肌细胞,而对照组左室心肌组织中未见心肌细胞凋亡.结论心肌细胞凋亡与糖尿病大鼠心力衰竭密切相关.     

血管紧张素Ⅳ对糖尿病大鼠胆碱乙酰转移酶表达及认知功能的影响

目的 观察血管紧张素Ⅳ(AngⅣ)对糖尿病大鼠海马胆碱乙酰转移酶(ChAT)表达及认知功能的影响.方法 38只SD大鼠随机分为正常对照组、糖尿病组和糖尿病+AngⅣ组,建立STZ糖尿病大鼠模型, Morris水迷宫测试大鼠学习和记忆能力,免疫组化观察大鼠海马ChAT的表达,RT-PCR检测ChAT mRNA水平的表达.结果 糖尿病+ AngⅣ组海马chAT及其mRNA表达与糖尿病组相比明显增高(P<0.05),糖尿病+ AngⅣ组大鼠学习和记忆成绩也明显优于糖尿病组(P<0.05).结论 AngⅣ对糖尿病大鼠认知功能有改善作用,其机制可能与ChAT表达增加有关.     

糖尿病大鼠胃肠功能紊乱时结肠组织中Cajal间质细胞的表达

目的观察糖尿病大鼠胃肠功能紊乱时结肠组织内Cajal间质细胞的分布及表达变化,探讨Cajal间质细胞在糖尿病胃肠功能紊乱发病机制中的作用。方法30只SD大鼠随机分为两组,糖尿病组20只,正常对照组10只。糖尿病组大鼠用链脲佐菌素单剂量腹腔注射建立糖尿病模型,对照组注射等量枸橼酸缓冲液。两组大鼠饲养6周后处死,计算胃肠推进率并且收集结肠组织标本。用免疫组化方法观察Cajal间质细胞在两组大鼠结肠组织内的分布和表达,用W estern b lot方法检测c-k it蛋白在两组大鼠结肠内的表达。结果糖尿病组大鼠胃肠推进率较对照组明显降低（P〈0.05）。免疫组化和W estern b lot检测都显示糖尿病大鼠结肠组织内Cajal间质细胞的表达较正常大鼠明显减少（P均〈0.05）。结论糖尿病大鼠结肠组织内Cajal间质细胞表达减少,推测与糖尿病大鼠胃肠功能紊乱有一定相关性。     

应用体视学方法比较糖尿病大鼠和正常大鼠海马的体积

目的用体视学方法比较正常大鼠和糖尿病大鼠的海马体积。方法通过链脲佐菌素(STZ)诱导建立糖尿病大鼠模型,成模12 w时,Morris水迷宫测试大鼠的空间学习和记忆能力,体视学方法测量大鼠海马体积。结果 Morris水迷宫测试中,糖尿病大鼠组潜伏期21.10 s(10.95~29.03 s)较正常大鼠组13.16 s(9.97~21.34 s)明显延长(P0.05),糖尿病组中心区停留时间百分比(15.03±3.36)%,较正常大鼠组(25.33±1.91)%明显下降(P0.05)。糖尿病大鼠海马平均体积小于正常大鼠组,但差异无统计学意义(P0.05)。结论糖尿病大鼠海马体积和正常大鼠相比无显著性变化,但存在明显的认知障碍。     

丝胶对2型糖尿病大鼠坐骨神经神经微丝蛋白表达的影响

目的观察丝胶对2型糖尿病大鼠坐骨神经神经微丝蛋白(NFP)表达的作用。方法 36只雄性SD大鼠随机分为正常对照组、糖尿病模型组和丝胶治疗组,每组12只。链脲佐菌素腹腔注射建立2型糖尿病大鼠模型并给予丝胶(2.4 g/kg)灌胃。SP免疫组织化学染色法观察大鼠坐骨神经NFP的表达。结果 NFP免疫阳性产物为棕黄色,位于坐骨神经的轴索。与正常对照组大鼠比较,糖尿病模型组大鼠坐骨神经NFP的表达明显降低(P<0.01);丝胶治疗组大鼠坐骨神经NFP的表达明显高于糖尿病模型组大鼠(P<0.05)。结论丝胶可通过上调糖尿病模型大鼠坐骨神经NFP的表达,发挥对糖尿病坐骨神经损伤的保护作用。     

大鼠实验性糖尿病的一种亚型

我们在制备大鼠糖尿病模型的实验中,其中一组动物注射链脲霉素后表现的糖尿病症状与成模糖尿病大鼠的表现有所不同,颇似临床隐性期糖尿病,我们将其称为糖尿病亚型。本文对此类大鼠糖尿病的症状特点与糖尿病成模大鼠的区别及其形成原因作一简单报道。 一、实验动物:受体为纯系DA大鼠,供体为纯系DA大鼠的仔鼠(生后5日内),本院动物室供给,体重250mg左右,雄性。     

糖尿病大鼠磷酸化表皮生长因子受体表达的改变及其与隐形皮肤损害的关系

目的探讨糖尿病大鼠皮肤的隐形损害现象,以及磷酸化的表皮生长因子受体（P-EGFR）在糖尿病皮肤中的表达与这种隐形损害的关系。方法对比观察不同病期的糖尿病大鼠模型背部和尾巴皮肤组织学改变以及超微结构变化,用免疫组化及蛋白印迹的方法检测P-EGFR在糖尿病大鼠皮肤中的表达。结果糖尿病大鼠皮肤存在组织学和超微结构的改变,p-EGFR在皮肤组织中的表达下降。结论P-EGFR在糖尿病大鼠皮肤组织中表达下调可能与糖尿病皮肤损害的发生有关。     

吸烟对2型糖尿病大鼠肾脏中期因子表达的影响

目的探讨中期因子在吸烟的2型糖尿病大鼠肾脏组织中的表达及对糖尿病肾病发生发展的作用。方法将60只大鼠分为正常对照组、2型糖尿病非吸烟组及2型糖尿病吸烟组,PCR法检测中期因子在各组大鼠肾脏组织中的表达。结果中期因子在2型糖尿病非吸烟组大鼠肾脏组织中的表达明显低于正常对照组,在吸烟2型糖尿病大鼠肾脏组织中的表达明显低于2型糖尿病非吸烟组及正常对照组。结论吸烟可以通过下调肾脏组织中期因子的表达促进糖尿病肾病的发生和发展。     

四磨汤对糖尿病大鼠降钙素基因相关肽及饥饿素的影响

目的 研究四磨汤对糖尿病大鼠降钙素基因相关肽( CGRP)及饥饿素的影响.方法 48只SD大鼠分为健康对照组、糖尿病组、糖尿病四磨汤低剂量治疗组、糖尿病四磨汤中剂量治疗组、糖尿病四磨汤高剂量治疗组及糖尿病中剂量预防组,每组8只.予糖尿病组及各干预组大鼠1％链脲佐菌素腹腔注射造模,健康对照组仅予柠檬酸母液注射.造模成功后8周,各干预组大鼠予低(0.15 ml·kg-1·d-1)、中(1.5ml·kg-1·d-1)、高(3.0 ml·kg-1·d-1)剂量四磨汤灌胃2周,对照组及糖尿病组予等体积0.9％NaCl溶液灌胃.预防组于造模成功后即开始予1.5 ml·kg-1·d-1四磨汤灌胃10周.药物干预结束后处死大鼠,取胃窦组织行实时PCR检测饥饿素、CGRP的表达.数据处理采用单因素方差分析和t检验.结果 糖尿病大鼠胃窦饥饿素基因水平较对照组无明显变化,但低、中剂量四磨汤干预后饥饿素表达水平高于糖尿病组(1.45±0.34、1.87±0.68比0.87±0.28,Dunnett's T3检验,P＜0.05),高剂量四磨汤干预对糖尿病大鼠饥饿素的表达无影响,四磨汤中剂量预防或治疗对糖尿病大鼠饥饿素的影响差异无统计学意义；糖尿病大鼠胃窦CGRP基因水平明显高于对照组(4.61±1.67比1.06±0.40,t=5.843,P＜0.01),低剂量四磨汤干预对糖尿病大鼠CGRP表达无影响,四磨汤中、高剂量干预可下调糖尿病大鼠CGRP的表达,四磨汤中剂量预防或治疗对糖尿病大鼠CGRP表达的影响差异无统计学意义.结论 四磨汤可促进糖尿病大鼠胃窦饥饿素的基因表达.糖尿病大鼠胃窦CGRP基因表达显著增加,但四磨汤可下凋糖尿病大鼠胃窦CGRP的基因表达水平.     

老龄2型糖尿病大鼠维生素D与胰岛素抵抗的关系

目的 观察老龄2型糖尿病大鼠维生素D水平与胰岛素抵抗(IR)的关系.方法 测定老龄2型糖尿病大鼠、维生素D3处理的老龄2型糖尿病大鼠、1-α(OH)D3处理的老龄2型糖尿病大鼠和正常老龄大鼠IR、血25-(OH) D3和1,25-(OH)2D3水平.正常血糖胰岛素钳夹技术(EICT)测定各组大鼠IR,用葡萄糖输注速率(GIR)表示IR情况,25-(OH)D3和1,25-(OH)2D3水平测定用放免法.结果 老龄2型糖尿病大鼠和正常老龄大鼠相比,GIR和1,25-(OH)2D3有显著降低,25-(OH)D3无显著差异.维生素D3处理的老龄2型糖尿病大鼠与老龄2型糖尿病大鼠相比,25-(OH)D3显著升高,但1,25-(OH)2D3无显著改变.1-α羟化维生素D3处理的老龄2型糖尿病大鼠与老龄2型糖尿病大鼠相比,25-(OH)D3无明显改变,1,25-(OH)2D3增加显著.维生素D3处理的老龄2型糖尿病大鼠、1-α(OH) D3处理的老龄2型糖尿病大鼠与2型糖尿病老龄大鼠相比,IR无显著差异.结论 老年2型糖尿病大鼠中维生素D与IR无显著相关性.     

通络方药对2型糖尿病大鼠心肌和主动脉iNOS基因表达的影响

目的观察通络方药（Tongluo Recipe,TLR）对2型糖尿病大鼠心肌和主动脉诱导型一氧化氮合酶（iNOS）基因表达的影响,探讨TLR在2型糖尿病（type 2 diabetes,T2DM）的干预作用和应用价值。方法30只雄性健康清洁级SD大鼠随机分为3组：正常对照组、T2DM组、T2DM＋TLR干预组,每组10只。T2DM＋TLR干预组大鼠TLR按0．4g·kg^-1·d^1剂量灌胃,1次,d,持续给药12W后处死取心肌、主动脉组织待测。利用实时定量逆转录多聚酶链反应（RT-PCR）方法测定各组大鼠心肌、主动脉诱导型一氧化氮合酶iNOS的基因表达水平。结果与正常对照组比较,2型DM组大鼠心肌和主动脉iNOS的mRNA表达明显降低（P〈0．01、P〈0．05）,而T2DM＋TLR干预组大鼠心肌和主动脉iNOS的mRNA表达较T2DM组明显升高（P〈0．01）。结论TLR可以增加T2DM大鼠心肌、主动脉iNOS的mRNA表达,从而增加NO合成,可能对T2DM具有防治意义。     

Prolactin (PRL) regulation of maternal behavior in rats: bromocriptine treatment delays and PRL promotes the rapid onset of behavior

Recent findings indicate that PRL helps stimulate the onset of maternal behavior in inexperienced hypophysectomized steroid-treated female rats. In a series of five experiments we have further examined the involvement of PRL in maternal behavior using nonhypophysectomized ovariectomized rats treated concurrently (type I) or sequentially (type II) with progesterone (P) and estradiol (E2) and administered either bromocriptine (to suppress endogenous PRL secretion) or bromocriptine plus ovine PRL. In Exp 1 plasma PRL concentrations were measured in ovariectomized rats treated for 2 weeks with a combination of E2 and P Silastic implants. Type I steroid-treated (2mm E2, days 1-24; three 30 mm P, days 3-13) rats exhibited elevated plasma PRL levels throughout the sampling period compared with nonsteroid-treated controls. In contrast, PRL concentrations in type II steroid-treated (P, days 3-13; E2, days 13-24) females were low (similar to controls) from days 3-13 when the type II steroid-treated females were exposed to P only. Like type I treated rats, PRL levels in type II steroid-treated rats were elevated from day 13 onward after E2 capsule insertion. In Exp 2, treatment of both type I and type II steroid-treated rats with bromocriptine (2 mg/kg, sc) twice daily beginning on treatment day 13 suppressed basal PRL concentrations and prevented the estrogen-induced diurnal PRL surge. Whereas PRL was effectively suppressed by bromocriptine in both steroid-treated groups, the absolute levels of PRL were lower in rats treated with the type II steroid regimen. Behavioral analyses in Exp 3, 4, and 5 revealed that bromocriptine administration, while failing to interfere with the onset of maternal behavior in rats treated with the type I concurrent steroid regimen, disrupted the onset of maternal care in rats treated with the type II sequential steroid regimen. When a separate set of type II steroid-treated rats was given both bromocriptine (2 mg/kg) plus ovine PRL (0.5 mg, sc) twice daily, maternal behavior rapidly appeared. Thus, suppression of endogenous PRL secretion delays the onset of maternal behavior in nonhypophysectomized steroid-primed rats, an effect prevented by concurrent administration of ovine PRL. In addition to providing further experimental support for PRL's role in maternal behavior, the development of this endocrine regimen provides researchers with a potentially fruitful model to examine neural sites and mechanisms of PRL regulation of maternal behavior in mammals.     

STZ诱导的2型糖尿病大鼠心肌组织TRPC7的表达上调

目的:观察2型糖尿病(T2DM)大鼠心肌组织损伤过程中,TRPC7的表达变化。方法:以高脂饲料喂养并辅以腹腔注射小剂量链脲佐菌素(Streptozotocin,STZ)来建立T2DM大鼠模型,采用蛋白印迹及免疫组化染色方法检测TRPC7在T2DM大鼠心肌组织的表达变化。结果:1T2DM大鼠造模成功且T2DM大鼠心肌组织发生损伤性变化:与正常组大鼠相比,T2DM组大鼠血糖明显升高且体重显著降低(P0.05);T2DM组大鼠心脏体积与质量显著减小(P0.05);T2DM组大鼠心脏质量指数(heart weight index,HWI)明显高于正常组(P0.05);2在T2DM大鼠心肌损伤过程中TRPC7表达上调:TRPC7在正常及T2DM大鼠心肌组织中均有表达,但与正常大鼠相比,T2DM大鼠心肌组织TRPC7蛋白的表达显著增高(P0.05)。结论:首次证实在损伤的T2DM大鼠心肌组织中,TRPC7的表达显著上调。     

Unmyelinated fiber sensory neuropathy differs in type 1 and type 2 diabetes

BACKGROUND: Neuropathic pain is common in diabetic patients. Degeneration of sensory C-fibers in peripheral nerve plays a prominent role in the generation of neuropathic pain. We examined degenerative changes of C-fibers in two rat models with type 1 and type 2 diabetes. METHODS: Type 1 insulinopenic BB/Wor and type 2 hyperinsulinemic diabetic BBZDR/Wor-rats of 8 months duration with equal exposure to hyperglycemia were examined. Thermal hyperalgesia was monitored using an infrared thermal probe. C-fiber size, number, frequencies of denervated Schwann cells, regenerating C-fibers, type 2 axon/Schwann cell relationship and collagen pockets in the sural nerve were examined morphometrically. Neurotrophic receptor expression was examined by Western blotting. Neurotrophins and neuropeptides were examined by ELISA. RESULTS: Type 1 rats showed increased thermal hyperalgesia followed by a decrease. Hyperalgesia in type 2 rats showed a slower progression. These findings were associated with a 50% (p < 0.001) loss of C-fibers, increased frequencies of denervated Schwann cells (p < 0.001), regenerating fibers (p < 0.001), collagen pockets (p < 0.001) and type 2 axon/Schwann cell relationship (p < 0.001) in type 1, but not in type 2 rats. Expression of insulin receptor, IGF-1R, TrkA and C was decreased in BB/Wor rats, whereas BBZDR/Wor rats showed milder or no deficits. NGF and NT-3 in sciatic nerve and substance P and calcitonin gene-related peptide in dorsal root ganglia were decreased in type 1, but not in type 2 rats. CONCLUSION: The more severe molecular, functional and morphometric abnormalities of nociceptive C-fibers in type 1 insulinopenic rats compared to type 2 hyperinsulinemic rats suggest that impaired insulin action may play a more important pathogenetic role than hyperglycemia per se.     

甲状腺功能亢进对大鼠中枢神经系统Ⅱ型脱碘酶mRNA表达的影响

目的观察甲状腺功能亢进(甲亢)大鼠中枢神经系统Ⅱ型脱碘酶mRNA(D2-mRNA)的表达。方法将Wistar大鼠分为对照组和甲亢组,甲亢组采用40 g／L甲状腺素灌胃。连续3周后定量荧光RT-PCR技术分析甲亢大鼠大脑、小脑、海马、脑干和脊髓中D2-mRNA表达的变化。结果甲亢大鼠大脑、小脑、海马、脑干和脊髓的D2-mRNA的表达均被抑制,与对照组比较,分别下调22．21％、45．57％、31．56％、34．79％、85．10％。结论甲亢时大鼠中枢神经系统的D2在转录水平受到抑制,说明D2对中枢神经系统自稳态的调节起着重要的作用。     

2型糖尿病对大鼠心肌缺血再灌注损伤救援激酶信号通路的影响

目的 探讨2型糖尿病(T2DM)对心肌缺血后适应(ischemic postconditioning,IPO )减轻心肌缺血再灌注损伤作用的影响及可能机制.方法　高脂饮食联合STZ诱导制成T2DM大鼠模型,将60只雄性Wistar大鼠随机分为正常大鼠缺血再灌注组(A组)、正常大鼠缺血后适应组(B组)、糖尿病大鼠后适应组(C组).3组均采用离体大鼠心脏Langendorff灌流方法　,全心停灌30 min,复灌60 min,制成心肌缺血再灌注模型.B、C组在再灌注开始前先给予再灌注10 s,全心停灌10 s,共6次循环的IPO.免疫组织化学染色及Western印迹法测定心肌磷酸化Akt,磷酸化糖原合成酶激酶(GSK-3β)的表达.结果 正常离体大鼠心肌IPO干预后磷酸化Akt及GSK-3β的表达增强;而对T2DM大鼠给予IPO处理后磷酸化Akt及GSK-3β的表达无增强,去磷酸化GSK-3β表达增强.结论 IPO对正常大鼠离体心脏缺血再灌注损伤有明确的保护作用,而对T2DM大鼠心肌缺血再灌注损伤无保护作用;其机制可能与糖尿病状态下影响再灌注损伤救援激酶信号通路,导致GSK-3β活性(去磷酸化水平)增高有关.     

2型糖尿病大鼠脂肪组织脂联素和骨骼肌组织脂联素受体R1基因表达的变化

半定量RT-PCR检测2型糖尿病大鼠模型脂肪组织脂联素及骨骼肌组织脂联素受体R1 mRNA表达。与正常大鼠比较，糖尿病大鼠骨骼肌组织脂联素受体R1基因表达无改变。糖尿病大鼠血清脂联素水平下降是由脂肪组织脂联素mRNA表达降低引起的，罗格列酮治疗可以使之改善。     

薏苡仁多糖对实验性2型糖尿病大鼠胰岛素抵抗的影响

目的 观察薏苡仁多糖对实验性2型糖尿病大鼠胰岛素抵抗的影响。方法 用小剂量链脲佐菌素（25mg/kg,iv)加高热量饲料（热卡：20.083J/g)建立实验性2型糖尿病大鼠模型，然后用薏苡仁多糖分三个剂量组（25、50、100mg/kg，ip)给药治疗2周，并测定葡萄糖耐量，血浆胰岛素以及肝糖原、肌糖原、肝细胞膜胰岛素受体结合率和肝葡萄糖激酶活性。结果 薏苡仁多糖能改善实验性2型糖尿病大鼠糖耐量异常，增加肝糖原量和肝葡萄糖激酶活性，且呈现一定的量效关系。但对血浆胰岛素水平及胰岛素受体最大结合率和受体最大结合容量均无影响。结论 薏苡仁多糖能够改善实验性2型糖尿病大鼠胰岛素抵抗，这可能与其调节糖代谢酶的活性有关。     

新型内源性气体信号分子硫化氢对低氧性肺血管胶原重塑的影响

目的研究大鼠低氧性肺血管重塑时硫化氢(H2S)对Ⅰ、Ⅲ型胶原蛋白在肺血管壁异常堆积的调节作用,进一步探讨H2S缓解低氧性肺血管重塑的作用机制。方法19只雄性Wistar大鼠随机分为对照组、低氧组、低氧+硫氢化钠(NaHS)组。低氧组和低氧+NaHS组大鼠共低氧21d,低氧+NaHS组大鼠每天低氧前腹腔注射H2S供体NaHS。低氧结束后,测定肺动脉平均压(mPAP),称重右心室(RV)和左心室+室间隔(LV+SP),计算RV/(LV+SP)。亚甲蓝分光光度法测定血浆中H2S含量。免疫组化染色检测Ⅰ、Ⅲ型胶原蛋白,原位杂交检测Ⅰ、Ⅲ型前胶原mRNA在肺血管壁表达。结果(1)与对照组相比,低氧组大鼠mPAP升高46%,RV/(LV+SP)增加41%,血浆H2S含量下降36%(P均<0·01);与低氧组相比,低氧+NaHS组大鼠的mPAP降低31%,RV/(LV+SP)减少24%,血浆H2S含量升高65%(P均<0·01)。(2)各组大鼠肺小型、中型肌性动脉中Ⅰ型胶原蛋白表达的比较:低氧组较对照组分别增加81%、62%(P<0·01);低氧+NaHS组较低氧组分别减少了32%、18%(P<0·01)。(3)各组大鼠肺小型、中型肌性动脉中Ⅰ型前胶原mRNA表达的比较:低氧组较对照组分别增加49%、68%(P<0·01);低氧+NaHS组较低氧组分别减少了31%、33%(P<0·01)。(4)各组大鼠肺小型肌性动脉中Ⅲ型胶原蛋白表达的比较:低氧组较对照组增加84%(P<0·01);低氧+NaHS组较低氧组减少了37%(P<0·01)。低氧组大鼠的肺中型肌性动脉中Ⅲ型胶原蛋白表达较对照组增加38%(P<0·01);但是与低氧+NaHS组相比无明显变化(P>0·05)。(5)各组大鼠肺小型、中型肌性动脉中Ⅲ型前胶原mRNA表达的比较:低氧组较对照组分别增加53%、17%(P<0·01);低氧+NaHS组较低氧组分别减少了45%、33%(P<0·01)。结论在大鼠低氧性肺血管胶原重塑时,H2S能够抑制Ⅰ、Ⅲ型胶原蛋白及其mRNA在肺血管壁的表达,此作用可能是其缓解低氧性肺血管重塑的作用机制之一。     

The insulin sensitizer pioglitazone improves the deterioration of ischemic preconditioning in type 2 diabetes mellitus rats

We investigated the effects of ischemic preconditioning (IP) on reperfusion arrhythmias in type 2 diabetic rats as well as the effects of the insulin sensitizer pioglitazone. Thirty-week-old OLETF rats with or without pioglitazone (10 mg/kgBW, orally) were used as a model for type 2 diabetes. LETO rats served as controls. The incidences and durations of reperfusion ventricular tachyarrhythmias (RVT) were evaluated using a working heart method. After 5 minutes of initial perfusion, the rats were divided into the following groups: 1) control rats without IP (CIP(-)), 2) control rats with IP (CIP(+)), 3) diabetic rats without IP (DIP(-)), 4) diabetic rats with IP (DIP(+)), 5) pioglitazone-treated diabetic rats without IP (TDIP(-)), and 6) pioglitazone-treated diabetic rats with IP (TDIP(+)). Three 2-minute cycles of global diastolic ischemia and 5 minutes of reperfusion before long ischemia were performed as IP. The incidence and duration of RVT in CIP(+) were significantly lower than in CIP(-). There was no significant difference in the duration of RVT between DIP(+) and DIP(-). However, the duration of RVT in TDIP(+) was significantly shorter than TDIP(-). These results suggested that the effects of IP on reperfusion arrhythmias are deteriorated in type 2 diabetic rats. The insulin sensitizer pioglitazone can improve the deterioration of IP against reperfusion arrhythmias in type 2 diabetic rats.