柴胡挥发油对大鼠肝能量代谢的影响

目的研究柴胡挥发油致大鼠肝毒性损伤的能量机制。方法大鼠ig给予柴胡挥发油0.19,0.28和0.42 m·lkg-1,连续15 d。Clark氧电极法测定肝线粒体呼吸耗氧量、呼吸控制率(RCR)和磷氧比值(P/O),测定ATP含量及定磷法测定ATP酶活性的变化。结果与正常对照组比较,柴胡挥发油0.42ml·kg-1可使大鼠肝线粒体和P/O从(1.76±0.28)%和1.28±0.38分别降至(0.76±0.12)%和0.71±0.21,呼吸耗氧量从(2.82±0.64)mol·min-1·g-1降至(1.04±0.23)mol·min-1·g-1,ATP含量从(1.00±0.18)μmol.g-1蛋白降至(0.72±0.13)μmol.g-1蛋白,Na+-K+-ATP酶、Mg2+-ATP酶和Ca2+-ATP酶活性分别从0.94±0.14,0.95±0.14和(0.97±0.16)mmol·h-1·g-1降至0.53±0.08,0.67±0.10和(0.65±0.11)mmol·h-1·g-1。柴胡挥发油0.28和0.19 ml·kg-1使大鼠肝脏线粒体PCR、P/O、呼吸耗氧量、ATP含量和ATP酶活性亦均显著降低(P<0.01)。结论柴胡挥发油可通过抑制线粒体呼吸功能、影响肝脏能量代谢造成肝毒性损伤。     

银杏叶提取物对糖尿病大鼠心肌线粒体呼吸控制率的影响

目的观察银杏叶提取物(EGb)对糖尿病大鼠心肌线粒体呼吸控制率的影响。方法30只SD大鼠随机分为正常对照组、糖尿病组和银杏叶治疗组,观察各组大鼠心肌线粒体超微结构,心肌线粒体呼吸控制率的变化。结果糖尿病大鼠心肌线粒体主要表现为肿胀,嵴变短,空泡化;呼吸控制率3态呼吸降低,呼吸控制率降低。银杏叶治疗组病变较糖尿病组明显减轻,治疗组心肌线粒体呼吸控制率3态呼吸及呼吸控制率与正常对照组无明显差异。结论EGb能提高心肌线粒体的呼吸控制率,从而对糖尿病大鼠心肌起保护作用。     

桑叶提取物通过调节肝线粒体融合分裂相关因子改善2型糖尿病大鼠的胰岛素抵抗

目的导致胰岛素抵抗的一个重要原因是线粒体融合和分裂动态平衡紊乱及由此引起的功能障碍。本实验研究桑叶提取物通过调节线粒体平衡相关因子来改善2型糖尿病(T2DM)的胰岛素抵抗(IR)。方法采用长期高脂肪饲养加小剂量链脲佐菌素(STZ,30 mg·kg~(-1),ip)诱导雌性大鼠T2DM动物模型,均匀分为4组,增加正常大鼠为对照组,灌胃给药4周后处死取肝组织。采用RT-PCR方法测定大鼠肝相关蛋白激酶的mRNA表达;采用Western印迹法测定相应蛋白的相对表达,并测定大鼠肝ATP含量、ATP酶活力和胰岛素含量(INS),计算胰岛素抵抗指数(HOME-IR)和胰岛素敏感指数(ISI)。结果与正常组相比,T2DM大鼠IR指数升高,Mfn2和PGC-1α蛋白表达下降,AMPK,Sirt1,Nrf1和Nrf2 mRNA表达显著降低,ERRαmRNA表达升高,ATP含量显著减少,ATP酶活力减弱(P<0.01);与模型组相比,桑叶提取物组降低T2DM大鼠INS(P<0.05),低剂量组上调大鼠肝Mfn2和PGC-1α蛋白表达,上调AMPK,Sirt1,Nrf1和Nrf2 mRNA表达(P<0.05),下调ERRαmRNA的表达,增加T2DM大鼠肝ATP含量和ATP酶活力(P<0.05)。结论桑叶提取物以调节T2DM大鼠肝线粒体平衡相关因子维持线粒体功能正常为机制,改善胰岛素抵抗。     

罗格列酮对2型糖尿病大鼠肝脏线粒体功能障碍的影响

目的探讨罗格列酮对2型糖尿病大鼠肝脏线粒体功能障碍的影响,为阐明糖尿病的发病机制以及罗格列酮治疗糖尿病的药理作用提供新的实验依据。方法采用高脂饲养加腹腔注射小剂量链脲佐菌素(35 mg.kg-1)诱导2型糖尿病大鼠;检测肝脏线粒体琥珀酸脱氢酶及细胞色素C氧化酶活性、线粒体膜电位、肝ATP含量等指标以评价线粒体功能;测定过氧化物酶体增殖物激活受体γ辅激活因子1α(PGC-1α)的mRNA水平及线粒体基因细胞色素C氧化酶亚基Ⅰ(COXⅠ)与核基因-βactin的拷贝数之比来反映线粒体的生物合成;并检测解偶联蛋白2(UCP2)的基因转录、NO含量及NOS活性、脂质过氧化产物MDA含量和抗氧化酶SOD活性等指标以探讨糖尿病大鼠肝脏线粒体功能障碍的可能机制。结果糖尿病大鼠血糖、血胰岛素水平显著升高,胰岛素敏感性指数明显降低,表明2型糖尿病大鼠模型建立成功。与正常大鼠相比,2型糖尿病大鼠肝脏线粒体琥珀酸脱氢酶及细胞色素C氧化酶活性下降、线粒体膜电位降低、ATP生成减少并伴有肝脏线粒体生物合成抑制,提示线粒体功能损害;此外,肝脏UCP2转录上调,同时伴肝MDA含量增加,SOD及NOS活性降低,NO含量减少。罗格列酮治疗8周后,不仅明显改善糖尿病大鼠肝脏线粒体功能的损害,而且增加肝脏线粒体生物合成。进一步研究揭示罗格列酮对糖尿病大鼠肝脏线粒体功能的保护作用可能与下调UCP2 mRNA水平,上调PGC-1α转录表达,降低体内氧化应激水平有关。结论罗格列酮对糖尿病大鼠肝脏线粒体功能障碍具有保护作用。     

促甲状腺素释放激素对创伤休克大鼠肝线粒体呼吸功能的影响

采用大鼠单侧股骨粉碎性骨折伴15％体重失血的模型,观察动物存活率,肝脏线粒体呼吸控制率(RCR),ADP/O值的变化以及ia TRH 5 mg·kg~(-1)对肝线枉体呼吸功能的保护作用,创伤休克时,肝脏线粒体RCR,ADP/O值显著降低,24 h大鼠存活率明显减少,TRH能明显提高肝线粒体RCR,ADP/O值以及休克动物存活率,提示TRH有明显改善休克大鼠肝线粒体氧化磷酸化功能的作用。     

心肺复苏后大鼠脑细胞线粒体呼吸功能的变化及左卡尼汀的干预作用

目的:研究心肺复苏后大鼠脑细胞线粒体呼吸功能的改变及左卡尼汀对其脑细胞线粒体呼吸功能的干预作用。方法:采用窒息合并0.5 mol/L冰氯化钾停跳液致大鼠心跳骤停5 min后开始心肺复苏的动物模型,SD大鼠88只,随机分为11组:对照组(假手术组),心肺复苏后3、12、24、48、72 h组,心肺复苏后左卡尼汀干预3、12、24、487、2 h组。每组均为8只大鼠。1 g/支的左卡尼汀溶于100 mL 0.9%NaCl注射液,按100 mg/kg的剂量给大鼠腹腔注射。取脑组织测定线粒体呼吸Ⅲ、Ⅳ态及呼吸控制率(RCR)、磷氧比(P/O)。结果:心肺复苏后大鼠脑细胞线粒体RCR和P/O明显下降;随着复苏成功后时间的延长,线粒体RCR和P/O维持在低水平;使用左卡尼汀干预后,RCR和P/O能接近正常。结论:心肺复苏后大鼠脑细胞线粒体呼吸功能明显下降,左卡尼汀对脑细胞呼吸功能有保护作用。     

叶卟啉衍生物对细胞膜和亚细胞器的光敏效应

叶卟啉衍生物(Chloroporphyrin deriva-tive,CPD_4)20mg·L~(-1)合并照光5min,产生显著光溶血。CPD_410ng·L~(-1)加光照10_(min),小鼠红细胞膜乙酰胆碱酯酶(AchEs)明显失活,CP_420mg·L~(-1)加光照10min,小鼠肝线粒体ATP酶和肝微粒体G—6—P酶显著受抑,CPD_410mg·L~(-1)加光照10min,小鼠红细胞膜脂质过氧化产物丙二醛(MDA)大大增加,CPD_4受光照激发后产生超氧阴离子自由基O_2 产量与CPD_4剂量和光照时间有关。     

糖尿病小鼠肝线粒体氧化损伤及其机制

目的:糖尿病是威胁人类健康的主要疾病之一,为了证明糖尿病的发生发展与氧化应激密切相关,从线粒体呼吸链角度探讨其机制。方法:用四氧嘧啶(Alloxan)建立实验性糖尿病小鼠模型,利用比色法分别从整体、组织和线粒体水平测定抗氧化酶活性,用铁氰化钾脉冲法测定线粒体呼吸活链II+III电子传递与质子泵出偶联(H+/2e)。结果:糖尿病小鼠GSH、GSH-Px分别比对照组显著降低(P<0.001),血清和肝组织、线粒体GSH-Px/MDA比值分别降低59.89%、40.69%和59.65%;线粒体呼吸链II+III总H+/2e显著降低24.76%(P<0.05),净H+/2e显著降低32.31%(P<0.05)。结论:实验性糖尿病小鼠肝功能损伤是氧化性损伤,氧化应激又是该损伤的结果,其原因与质子漏增加,电子传递与质子泵出脱偶联有关,导致自由基增加,无效耗氧增加,线粒体受损。     

Ebselen对自由基诱发的皮层神经元和皮层线粒体脂质过氧化损伤的保护作用

观察了ebselen对超氧阴离子O^·-₂和羟自由基·OH诱发的体外培养大鼠皮层神经元乳酸脱氢酶(lactic dehydrogenase,LDH)释放,和TBARS(thiobarbituric acid reactive substance)含量升高及制备的皮层线粒体TBARS含量升高的影响。结果表明:超氧阴离子和羟自由基引起了培养神经元和线粒体明显的损伤。浓度在5～50μmol·L^-1之间,ebselen能剂量依赖性地抑制LDH释放和TBARS含量的增加,对线粒体的TBARS含量升高也有显著的抑制作用。但浓度为0.2～50μmol·L^-1时,药物无直接清除超氧阴离子和羟自由基的活性。因此,ebselen对氧自由基诱发的神经元脂质过氧化损伤有拮抗作用,这种作用与直接清除自由基无关。     

氧化还原状态的改变控制手霉素诱导HL-60白血病细胞凋亡

目的研究手霉素对HL-60白血病细胞的作用,探讨其作用机制,主要是线粒体的改变。方法使用人的白血病细胞株HL-60细胞。MTT细胞毒性测定评价对白血病细胞的作用,使用Annexin V和一氧化氮(nitric oxide,NO)染料标记细胞,应用流式细胞仪术检测细胞内NO生成和细胞凋亡。细胞内超氧阴离子通过二氢乙啶(dihydroethidium,DHE)测定。应用化学发光法测定超氧歧化酶(superoxide dismutase,SOD)活性。采用荧光法测定谷胱甘肽(glutathi-one,GSH),萤光素-萤光素酶发光法测定ATP含量。免疫印迹技术检测细胞色素C和Mn-SOD的表达。结果手霉素引起HL-60细胞活性的下降,且呈剂量依赖性。手霉素诱导产生反应性氧基(reactive oxygen species,ROS):NO和超氧阴离子,降低GSH,但不影响SOD。手霉素诱导线粒体降低细胞ATP的含量,线粒体肿胀和细胞色素C从线粒体释放到细胞质。手霉素诱导的凋亡与ROS的增加有关。用N-乙酰基-L-半胱氨酸(N-acetyl-L-cysteine,NAC)抑制ROS可保护HL-60细胞逃避手霉素的细胞毒作用和避免手霉素诱导的凋亡。结论细胞内ROS的产生对手霉素的细胞毒作用起非常重要的作用。手霉素通过包括上游ROS产生,线粒体形态改变和细胞色素C释放的线粒体途径,诱导白血病细胞凋亡。     

The association effect of insulin and clonazepam on oxidative stress in liver of an experimental animal model of diabetes and depression

Abstract

Context: It is known that oxidative stress occurs in peripheral blood in an experimental animal model of diabetes and depression, and acute treatment with insulin and clonazepam (CNZ) has a protective effect on oxidative stress in this model.

Objective: This study evaluated the effect of insulin plus CNZ on oxidative stress parameters in the liver of diabetic male rats induced with streptozotocin (STZ) and subjected to forced swimming test (FST).

Materials and methods: Diabetes was induced by a single intraperitoneal (i.p.) dose of STZ 60?mg/kg in male Wistar rats. Insulin (4?IU/kg) plus CNZ acute i.p. treatment (0.25?mg/kg) was administered 24, 5 and 1?h before the FST. Nondiabetic control rats received i.p. injections of saline (1?mL/kg). Protein oxidative damage was evaluated by carbonyl formation and the antioxidant redox parameters were analyzed by the measurements of enzymatic activities of the superoxide dismutase (SOD), catalase and glyoxalase I (GLO). Glycemia levels also were determined.

Results: Our present study has shown an increase in carbonyl content from diabetic rats subjected to FST (2.04?±?0.55), while the activity of catalase (51.83?±?19.02) and SOD (2.30?±?1.23) were significantly decreased in liver from these animals, which were reverted by the treatment. Also, the activity of GLO (0.15?±?0.02) in the liver of the animals was decreased.

Discussion and conclusion: Our findings showed that insulin plus CNZ acute treatment ameliorate the antioxidant redox parameters and protect against protein oxidative damage in the liver of diabetic rats subjected to FST.     

匹诺塞林对急性局灶性脑缺血大鼠脑线粒体功能的影响

目的考察匹诺塞林对大鼠急性局灶性脑缺血组织能量代谢及线粒体功能的影响。方法制备永久性大鼠大脑中动脉栓塞(pMCAO)模型,大鼠随机分为假手术组、模型组、匹诺塞林给药组(1、3、10 mg.kg-1)、尼莫地平给药组(3mg.kg-1)。给药组于手术后10 min、12 h分别给予静脉注射,假手术组与模型组给予生理盐水。于手术24 h应用生化方法检测脑组织中LDH的活性,HPLC法检测大鼠脑组织ATP、ADP、AMP、磷酸肌酸含量。通过检测线粒体超氧化物歧化酶(Mn-SOD)、线粒体Ca2+-ATP酶活性,超氧阴离子含量、线粒体膜肿胀度、线粒体钙离子含量综合评价线粒体功能。结果匹诺塞林(3、10 mg.kg-1)给药组大鼠缺血脑组织中乳酸脱氢酶活性降低,能量指数比模型组分别提高了34.6%和45.8%(P<0.05);匹诺塞林(10 mg.kg-1)组线粒体SOD活性提高了24.4%、Na+,K+-ATP酶、Ca2+-ATP酶活性分别升高了24.9%及34.0%,线粒体钙离子浓度降低了22.0%,与模型组相比差异均具有显著性(P<0.05)。匹诺塞林(3、10 mg.kg-1)组线粒体超氧阴离子水平分别降低了20.2%及30.6%、线粒体肿胀程度分别降低了26.1%及46.0%,与模型组相比差异均具有显著性(P<0.05)。结论匹诺塞林可减轻大鼠脑缺血后能量损伤,提高脑组织抗缺血缺氧能力,其对线粒体功能的保护作用可能是改善缺血脑组织能量代谢的重要机制。     

Cytotoxicity and mitochondrial dysfunction of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in isolated rat hepatocytes

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental contaminant that induces hepatic and extrahepatic oxidative stress and the mechanisms of TCDD-induced reactive oxygen species are not fully investigated. Moreover, the potential toxicity of TCDD in isolated rat hepatocytes is not fully explored. The aim of the current study was to explore the possible cytotoxic effect of TCDD on primary rat hepatocytes and to explore the impact of mitochondria in TCDD-induced toxicity. Hepatocytes were isolated from adult rat liver and incubated with 0, 5, 10 or 15 nM of TCDD for 24, 48 and 72 h. Cell viability, lactate dehydrogenase (LDH) leakage into media along with reactive oxygen species (ROS) generation and hydrogen peroxide (H₂O₂) production, mitochondrial membrane potential (Δψ_m), superoxide dismutase (SOD), catalse (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), total thiol contents, hepatic aryl hydrocarbon hydroxylase (AHH), and ethoxyresorufin O-deethylase (EROD) were performed in hepatocytes. In addition, superoxide anion generation, lipid peroxidation (LPO), mitochondrial protein carbonyl content and respiratory chain complexes II and IV were assayed in hepatocyte mitochondria. Cell viability was significantly decreased while LDH leakage into media was significantly increased in a dose and time related manner. ROS generation and H₂O₂ production along with EROD and AHH activities were significantly increased in hepatocytes in the same pattern. The antioxidant enzymes SOD, CAT, GPx and GR and the non-enzymatic protein thiols, in addition to Δψ_m were significantly decreased in hepatocytes in a concentration and time dependent pattern. On the other side, mitochondrial superoxide anion along with LPO and mitochondrial protein carbonyl content were significantly increased while the respiratory chain complexes II and IV activities were significantly decreased in hepatocyte mitochondria. This effect may lead to disruption in the functional integrity of hepatocytes and hepatocyte mitochondria. In conclusion, our data clearly show that TCDD induces hepatocyte toxicity and mitochondrial dysfunction by a mechanism involving generation of ROS. Mitochondria might be the primary source of (or at least contribute to) the oxidative stress response and resulting toxicological outcomes elicited by TCDD.     

牛磺酸对2型糖尿病大鼠胰腺线粒体氧化应激的影响

目的探讨牛磺酸对糖尿病大鼠胰腺线粒体氧化应激的影响。方法将30只Wistar大鼠随机分为正常对照组、糖尿病组(DM组)和牛磺酸治疗组(Tau组,采用20g.L-1牛磺酸生理盐水溶液治疗,200mg·kg-1),前两组注射等体积的生理盐水溶液。8wk后,测3组大鼠血浆葡萄糖、胰岛素、丙二醛(MDA),胰腺线粒体MDA、Ca2+、超氧化物歧化酶(SOD)及Na+,K+-ATP酶(Na+,K+-ATPase)和Ca2+,Mg2+-ATP酶(Ca2+,Mg2+-ATPase)的活性。结果①DM组大鼠血糖、MDA和胰腺线粒体MDA、Ca2+含量明显高于对照组(P<0.01),而血浆胰岛素水平、SOD、Na+,K+-AT-Pase和Ca2+,Mg2+-ATPase活性明显降低(P<0.05)。②Tau组大鼠血糖、MDA及胰腺线粒体Ca2+、MDA含量较DM组明显降低(P<0.05),血浆胰岛素水平、SOD、Na+,K+-ATPase和Ca2+,Mg2+-ATPase活性明显升高(P<0.05)。结论牛磺酸可减轻2型糖尿病大鼠胰腺线粒体氧化应激水平。     

Protective effect of boldine on oxidative mitochondrial damage in streptozotocin-induced diabetic rats.

Increased oxidative stress has been suggested to be involved in the pathogenesis and progression of diabetic tissue damage. Several antioxidants have been described as beneficial for oxidative stress-associated diseases. Boldine ([s]-2,9-dihydroxy-1, 10-dimethoxyaporphine) is a major alkaloid found in the leaves and bark of boldo (Peumus boldus Molina), and has been shown to possess antioxidant activity and anti-inflammatory effects. From this point of view, the possible anti-diabetic effect of boldine and its mechanism were evaluated. The experiments were performed on male rats divided into four groups: control, boldine (100 mg kg(-1), daily in drinking water), diabetic [single dose of 80 mg kg(-1)of streptozotocin (STZ), i.p.] and diabetic simultaneously fed with boldine for 8 weeks. Diabetic status was evaluated periodically with changes of plasma glucose levels and body weight in rats. The effect of boldine on the STZ-induced diabetic rats was examined with the formation of malondialdehydes and carbonyls and the activities of endogenous antioxidant enzymes (superoxide dismutase and glutathione peroxidase) in mitochondria of the pancreas, kidney and liver. The scavenging action of boldine on oxygen free radicals and the effect on mitochondrial free-radical production were also investigated. The treatment of boldine attenuated the development of hyperglycemia and weight loss induced by STZ injection in rats. The levels of malondialdehyde (MDA) and carbonyls in liver, kidney and pancreas mitochondria were significantly increased in STZ-treated rats and decreased after boldine administration. The activities of mitochondrial manganese superoxide dismutase (MnSOD) in the liver, pancreas and kidney were significantly elevated in STZ-treated rats. Boldine administration decreased STZ-induced elevation of MnSOD activity in kidney and pancreas mitochondria, but not in liver mitochondria. In the STZ-treated group, glutathione peroxidase activities decreased in liver mitochondria, and were elevated in pancreas and kidney mitochondria. The boldine treatment restored the altered enzyme activities in the liver and pancreas, but not the kidney. Boldine attenuated both STZ- and iron plus ascorbate-induced MDA and carbonyl formation and thiol oxidation in the pancreas homogenates. Boldine decomposed superoxide anions, hydrogen peroxides and hydroxyl radicals in a dose-dependent manner. The alkaloid significantly attenuated the production of superoxide anions, hydrogen peroxide and nitric oxide caused by liver mitochondria. The results indicate that boldine may exert an inhibitory effect on STZ-induced oxidative tissue damage and altered antioxidant enzyme activity by the decomposition of reactive oxygen species and inhibition of nitric oxide production and by the reduction of the peroxidation-induced product formation. Boldine may attenuate the development of STZ-induced diabetes in rats and interfere with the role of oxidative stress, one of the pathogeneses of diabetes mellitus.     

Protection of mitochondrial system by Hippophae rhamnoides L. against radiation-induced oxidative damage in mice

The whole extract of the fresh berries of Hippophae rhamnoides L. (RH-3), which has been reported to provide protection to whole mice, various tissues, cells and cell organelles against lethal irradiation, was further investigated for its effects on mitochondria isolated from mouse liver. Superoxide anion, reduced (GSH) and oxidized glutathione (GSSG) levels, NADH-ubiquinone oxidoreductase (complex I), NADH-cytochrome c oxidoreductase (complex I/II), succinate-cytochrome c oxidoreductase (complex II/III), mitochondrial membrane potential (MMP), lipid peroxidation (LPx) and protein oxidation (PO) were determined for RH-3-mediated radioprotective manifestation. Pre-irradiation treatment of mice with RH-3 (30 mg kg(-1,) i. p.; single dose; -30 min) significantly inhibited the radiation-induced increase in superoxide anions, GSSG, thiobarbituric acid reactive substances (TBARS), complex I, complex I/III activity and MMP maximally at 4 h (P < 0.05). This treatment inhibited the oxidation of proteins (P < 0.05) at all the time periods studied here. This study suggests that pre-irradiation treatment of mice with RH-3 protects the functional integrity of mitochondria from radiation-induced oxidative stress.     

毛兰素通过 JNK/c-Jun信号通路对 2型糖尿病大鼠肝脏损伤的保护作用机制研究

目的基于 c-Jun氨基末端激酶( JNK)/c-Jun信号通路对氧化应激反应的调控作用,研究毛兰素对 2型糖尿病大鼠肝脏损伤的保护作用。方法于 2021年 10月至 2022年 2月腹腔注射链脲佐菌素构建糖尿病大鼠模型,将造模成功大鼠分为模型组、毛兰素低剂量组( 10 mg/kg)、毛兰素高剂量组( 40 mg/kg)及罗格列酮组( 1.25 mg/kg)、毛兰素( 40 mg/kg)+JNK激活组(5 mg/ kg),每组 10只,另取正常饲养大鼠 10只作为对照组。连续给药,6周后,通过血糖仪和胰岛素放射免疫分析试剂盒检测空腹血糖( FBG)、空腹胰岛素( FINS)水平,计算胰岛素抵抗指数( HOMA-IR)及胰岛素敏感指数( ISI);天平称取大鼠体质量和肝质量,计算肝脏指数;试剂盒检测丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶( AST)、总超氧化物歧化酶( T-SOD)、谷胱甘肽过氧化物酶( GSH-Px)活性及丙二醛(MDA)含量; HE染色观察肝脏组织病理学变化; western blotting法检测肝脏组织中 JNK/c-Jun信号通路相关蛋白表达。结果与对照组相比,模型组肝脏指数［( 4.26±0.12)g/100 g比( 2.24±0.09)g/100 g］、 FBG［( 21.49±1.78)mmol/L比( 5.14±0.45)mmol/L］、 FINS［( 80.17±6.38)mmol/L比( 22.35±2.04)mmol/L］、 HOMA-IR［( 76.46±6.56)比( 5.11±1.12)］、 ALT［( 138.71±10.21)U/L比( 70.29±5.54)U/L］和 AST活性［( 77.21±5.08)U/L比( 40.38±3.27)U/L］、 MDA含量［( 13.45±1.34)nmol/mg prot比( 3.72±0.87)nmol/mg prot］、 JNK/c-Jun信号通路相关蛋白表达均明显升高( P<0.05),体质量、 ISI［( ?7.45±0.18)比( ?4.74±0.11)］、 SOD［( 100.79±11.22)U/mg prot比( 223.46±19.86)U/mg prot］和 GSH-Px活性［( 24.42±1.74)U/mg prot比(56.79±3.18)U/mg prot］明显降低( P<0.05),且肝脏组织病理损伤较为严重;与模型组相比,毛兰素低剂量组、毛兰素高剂量组和罗格列酮组肝脏指数、 FBG、FINS、HOMA-IR、ALT和 AST活性、 MDA含量、 JNK/c-Jun信号通路相关蛋白表达均明显降低( P<0.05),体质量、 ISI、SOD和 GSH-Px活性明显升高( P<0.05)减轻肝脏损伤程度;与毛兰素高剂量组相比,毛兰素低剂量组、毛兰素+JNK激活组肝脏指数、 FBG、FINS、HOMA-IR、ALT和 AST活性、 MDA含量、 JNK/c-Jun信号通路相关蛋白表达均明显升高(P<0.05)体质量、 ISI、SOD和 GSH-Px活性明显降低( P<0.05),肝脏损伤恢复缓慢。结论毛兰素可通过调控 JNK/c-Jun信号通路,抑制,JNK/c-Jun通路蛋白表达,从而缓解氧化应激反应,改善糖尿病大鼠肝脏损伤。     

Effect of the sulphonylurea glibenclamide on liver and kidney antioxidant enzymes in streptozocin-induced diabetic rats

BACKGROUND: Alterations in catalase (CAT) and superoxide dismutase (SOD) activity have been reported in diabetes mellitus. Glibenclamide (glyburide), a member of the second-generation sulphonylureas, provides effective treatment for patients with moderate diabetes. The action of the liver plays an important role in its glucose-lowering effect, suggesting that glibenclamide also exerts a direct effect on liver enzyme activities. OBJECTIVE: To evaluate the effect of glibenclamide on the activities of antioxidant enzymes (CAT and SOD) in liver and kidney tissue of diabetic rats. METHODS: Thirty-nine rats were included in this study. Moderate diabetes mellitus was induced with streptozocin (freshly dissolved in citrate buffer, ph 4.5) 55 mg/kg in 22 rats. Eight of these diabetic rats were left untreated, insulin was administered to six diabetic rats, and glibenclamide was administered to eight rats with moderate diabetes. Liver and kidney CAT and SOD activities were measured in all rats. RESULTS: Hepatic CAT and SOD activities were significantly reduced in diabetic animals (p < 0.05 for both activities). Glibenclamide treatment of diabetic rats for 5 weeks reversed the changes observed in diabetic liver tissues (p < 0.05). However, renal CAT and SOD activities were unchanged. In addition, high blood glucose levels of diabetic rats were decreased following glibenclamide treatment. CONCLUSION: Administration of glibenclamide to diabetic rats reversed diabetes-induced changes, suggesting that glibenclamide may directly increase liver CAT and SOD activity.     

西红花酸对阿霉素所致大鼠心肌线粒体损伤的影响

目的：研究西红花酸对阿霉素所致大鼠心肌线粒体损伤的保护作用。方法：建立阿霉素致大鼠心脏毒性模型，观察西红花酸对心肌线粒体膜电位、线粒体DNA断裂程度、细胞色素C氧化酶活性及其亚基ⅡmRNA表达的影响；测定心肌线粒体超氧阴离子含量及谷胱甘肽过氧化物酶（GSH-PX）活性。结果：与模型组相比，西红花酸可明显升高线粒体膜电位，降低线粒体DNA断裂程度，提高细胞色素C氧化酶活性及其亚基ⅡmRNA表达水平，显著降低心肌线粒体超氧阴离子含量，提高GSH—PX活性。结论：西红花酸能明显减轻阿霉素所致大鼠心肌线粒体损伤。     

Regulatory mechanism of the cytoplasmic pH by H(+)-adenosinetriphosphatase

Nature prefers simplicity. Streptococcal cytoplasmic pH is regulated in a simple biological manner: change in the amount of the adenosinetriphosphatase (H(+)-ATPase). This enzyme is identical to the F0F1-complex of oxidative phosphorylation, which synthesizes adenosinetriphosphate in mitochondria and most of bacteria, whereas it is used as a regulator of the cytoplasmic pH in streptococci which have no respiratory chain. Eukaryotes use the another type of H(+)-ATPase to regulate the internal pH. Thus, the evolutional process of H(+)-ATPase is quite interesting.