Renal blood perfusion in GK rats using targeted contrast enhanced ultrasonography

Objective: To explore application of targeted contrast enhanced ultrasonography in diagnosis of early stage vascular endothelial injury and diabetic nephropathy. Methods: Targeted Sono VueTM microbubble was prepared by attaching anti-TM monoclonal antibody to the surface of ordinary micro-bubble Sono Vue by biotin-avidin bridge method and ultrasonic instrument was used to evaluate the developing situation of targeted microbubble in vitro. Twenty 12-week-old male GK rats and 20 Wistar rats were enrolled in this study, and were randomly divided into targeted angiography group and ordinary angiography group. Targeted microbubbles Sono VueTM or general microbubble Sono Vue were rapidly injected to the rats via tail vein; the developing situation of the two contrast agents in rats kidneys was dynamically observed. Time intensity curve was used to analyse rat kidney perfusion characteristics in different groups. Results: Targeted ultrasound microbubble Sono Vue-TM was successfully constructed, and it could be used to develop an external image. Targeted microbubbles Sono Vue-TM enabled clear development of experimental rat kidney. Time intensity curve shapes of rat kidney of the two groups showed as single apex with steep ascending and slowly descending branch. Compared with the control group, the rising slope of the GK rat renal cortex, medulla in targeted angiography group increased(P<0.05); the peak intensity of medulla increased(P<0.05), and the total area under the curve of medulla increased(P<0.05). Compared with control group, the ascending branch of the GK rat in renal cortex, medulla in ordinary angiography group increased(P<0.05). The peak intensity of the curve increased(P<0.05), and the total area under the curve increased(P<0.05). Compared with the ordinary angiography group, the peak of GK rat medullacurve in targeted angiography group intensity increased(P<0.05), and the total area under the curve increased(P<0.05). Conclusions: Targeted microbubbles Sono VueTM can make a clear development of experimental rat kidney, its stable performance meet the requirement of ultrasonic observation time limit, and it can reflect early changes of blood perfusion in GK rat kindey.

Characterization of gut microbial and metabolite alterations in faeces of Goto Kakizaki rats using metagenomic and untargeted metabolomic approach

BACKGROUND In recent years,the incidence of type 2 diabetes(T2DM)has shown a rapid growth trend.Goto Kakizaki(GK)rats are a valuable model for the study of T2DM and share common glucose metabolism features with human T2DM patients.A series of studies have indicated that T2DM is associated with the gut microbiota composition and gut metabolites.We aimed to systematically characterize the faecal gut microbes and metabolites of GK rats and analyse the relationship between glucose and insulin resistance.AIM To evaluate the gut microbial and metabolite alterations in GK rat faeces based on metagenomics and untargeted metabolomics.METHODS Ten GK rats(model group)and Wistar rats(control group)were observed for 10 wk,and various glucose-related indexes,mainly including weight,fasting blood glucose(FBG)and insulin levels,homeostasis model assessment of insulin resistance(HOMA-IR)and homeostasis model assessment ofβcell(HOMA-β)were assessed.The faecal gut microbiota was sequenced by metagenomics,and faecal metabolites were analysed by untargeted metabolomics.Multiple metabolic pathways were evaluated based on the differential metabolites identified,and the correlations between blood glucose and the gut microbiota and metabolites were analysed.RESULTS The model group displayed significant differences in weight,FBG and insulin levels,HOMA-IR and HOMA-βindexes(P<0.05,P<0.01)and a shift in the gut microbiota structure compared with the control group.The results demonstrated significantly decreased abundances of Prevotella sp.CAG:604 and Lactobacillus murinus(P<0.05)and a significantly increased abundance of Allobaculum stercoricanis(P<0.01)in the model group.A correlation analysis indicated that FBG and HOMA-IR were positively correlated with Allobaculum stercoricanis and negatively correlated with Lactobacillus murinus.An orthogonal partial least squares discriminant analysis suggested that the faecal metabolic profiles differed between the model and control groups.Fourteen potential metabolic biomarkers,including glycochenodeoxycholic acid,uric acid,13(S)-hydroxyoctadecadienoic acid(HODE),N-acetylaspartate,β-sitostenone,sphinganine,4-pyridoxic acid,and linoleic acid,were identified.Moreover,FBG and HOMA-IR were found to be positively correlated with glutathione,13(S)-HODE,uric acid,4-pyridoxic acid and allantoic acid and negatively correlated with 3-α,7-α,chenodeoxycholic acid glycine conjugate and 26-trihydroxy-5-β-cholestane(P<0.05,P<0.01).Allobaculum stercoricanis was positively correlated with linoleic acid and sphinganine(P<0.01),and 2-methyl-3-hydroxy-5-formylpyridine-4-carboxylate was negatively associated with Prevotella sp.CAG:604(P<0.01).The metabolic pathways showing the largest differences were arginine biosynthesis;primary bile acid biosynthesis;purine metabolism;linoleic acid metabolism;alanine,aspartate and glutamate metabolism;and nitrogen metabolism.CONCLUSION Metagenomics and untargeted metabolomics indicated that disordered compositions of gut microbes and metabolites may be common defects in GK rats.

Effect of berberine on hyperglycaemia and gut microbiota composition in type 2 diabetic Goto-Kakizaki rats

BACKGROUND A recent investigation showed that the prevalence of type 2 diabetes mellitus(T2DM)is 12.8%among individuals of Han ethnicity.Gut microbiota has been reported to play a central role in T2DM.Goto-Kakizaki(GK)rats show differences in gut microbiota compared to non-diabetic rats.Previous studies have indicated that berberine could be successfully used to manage T2DM.We sought to understand its hypoglycaemic effect and role in the regulation of the gut microbiota.AIM To determine whether berberine can regulate glucose metabolism in GK rats via the gut microbiota.METHODS GK rats were acclimatized for 1 wk.The GK rats were randomly divided into three groups and administered saline(Mo),metformin(Me),or berberine(Be).The observation time was 8 wk,and weight,fasting blood glucose(FBG),insulin,and glucagon-like peptide-1(GLP-1)were measured.Pancreatic tissue was observed for pathological changes.Additionally,we sequenced the 16S rRNA V3-V4 region of the gut microbiota and analysed the structure.RESULTS Compared with the Mo group,the Me and Be groups displayed significant differences in FBG(P<0.01)and GLP-1(P<0.05).A significant decrease in weight and homeostatic model assessment-insulin resistance was noted in the Be group compared with those in the Me group(P<0.01).The pancreatic islets of the Me-and Be-treated rats showed improvement in number,shape,and necrosis compared with those of Mo-treated rats.A total of 580 operational taxonomic units were obtained in the three groups.Compared to the Mo group,the Me and Be groups showed a shift in the structure of the gut microbiota.Correlation analysis indicated that FBG was strongly positively correlated with Clostridia_UCG-014(P<0.01)and negatively correlated with Allobaculum(P<0.01).Body weight showed a positive correlation with Desulfovibrionaceae(P<0.01)and a negative correlation with Akkermansia(P<0.01).Importantly,our results demonstrated that Me and Be could significantly decrease Bacteroidetes(P<0.01)and the Bacteroidetes/Firmicutes ratio(P<0.01).Furthermore,Muribaculaceae(P<0.01;P<0.05)was significantly decreased in the Me and Be groups,and Allobaculum(P<0.01)was significantly increased.CONCLUSION Berberine has a substantial effect in improving metabolic parameters and modulating the gut microbiota composition in T2DM rats.

The pattern of plasma BCAA concentration and liver Bckdha gene expression in GK rats during T2D progression

Background: This study was conducted to measure the concentration of branched chain amino acid(BCAA) in different species and detect the expression pattern of the liver Bckdha gene in Goto-Kakizaki(GK) rats during type 2 diabetes(T2D)progression.Methods: We measured the concentration of BCAA in GK rats, induced T2D cynomolgus monkeys and T2D humans by liquid chromatography tandem mass spectrometry, and used real-time quantitative PCR to analyze the gene expression of Bckdha and Bckdk, which encode the rate-limiting enzymes in catabolism of,respectively, branched chain amino acids and branched chain α-keto acid dehydrogenase kinase.Results: In this study, we showed that GK rat BCAA concentrations were significantly reduced at 4 and 8 weeks(P < 0.05 and P < 0.01, respectively), while the expression of Bckdha in GK rat liver was increased at 4 and 8 weeks(1.62-fold and1.93-fold, respectively). The BCAA concentrations were significantly reduced in diet-induced T2D cynomolgus monkeys(P < 0.01), but significantly increased in T2D humans(P < 0.001).Conclusions: Our results showed that BCAA concentrations changed at different times and by different amounts in different species and during different periods of T2D progress, and the significant changes of BCAA concentration in the three species indicated that BCAA might participate in the progress of T2D. The results suggested that the increased expression of Bckdha in GK rat liver might partially explain the reduced plasma BCAA concentration at 4 and 8 weeks. Further studies are required to investigate the exact mechanism of BCAA changes in non-obese T2D.

基于Wnt/β-catenin信号通路探讨通络糖泰方对糖尿病周围神经病变GK大鼠作用机制

目的探讨通络糖泰(Tong luo tang tai,TLTT)对糖尿病周围神经病变(Diabetic peripheral neuropathy,DPN)GK大鼠Wnt/β-catenin信号通路的影响。方法将50只GK大鼠随机分为模型组、TLTT高、中、低剂量组、西药组,每组10只,另取10只wistar大鼠作为正常组。除正常组外,其余各组进行高脂饲养制备DPN大鼠模型,15周后制备DPN模型成功,对各组大鼠进行灌胃治疗。TLTT高、中、低剂量组分别给予中药TLTT 28 g·kg^(-1)、14 g·kg^(-1)、7 g·kg^(-1),西药组给予二甲双胍100 mg·kg^(-1)和弥可保0.2 mg·kg^(-1)剂量灌胃。各组大鼠每天1次,连续给药8周后,检测各组大鼠的一般状态、空腹血糖(Fasting blood sugar,FBS)、热缩足潜伏期(Thermal withdrawal latency,TWL)、坐骨神经传导速度(Motor nerve conduction velocity,MNCV),透射电镜观察坐骨神经组织的病理改变,Real-time PCR、Western blot分别检测坐骨神经中无翅型MMTV整合位点家族成员3A(Wnt3a)、β连环蛋白(β-catenin)、糖原合成激酶-3β(Glycogen synthase kinase-3β,GSK-3β)及Wnt信号通路上的拮抗剂(WNT inhibitory factor-1,Wif-1)mRNA和蛋白表达水平。结果与正常组相比,模型组一般状态较差且坐骨神经病理超微结构病变显著,其FBS水平升高(P<0.01),TWL水平下降(P<0.01),MNCV明显减慢(P<0.01),模型组Wnt3a、β-catenin、GSK-3βmRNA和蛋白表达水平均减少(P<0.05),Wif-1mRNA和蛋白表达水平增多(P<0.01)。经药物干预后,与模型组相比,TLTT高、中、低、剂量和西药组一般情况及坐骨神经病理超微结构得到改善,FBS水平下降(P<0.01),TWL水平升高(P<0.05),TLTT各剂量组和西药组MNCV明显改善(P<0.01),TLTT高剂量组和西药组Wnt3a mRNA显著增加(P<0.05),TLTT高剂量组和西药组Wif-1 mRNA显著降低(P<0.05),TLTT高剂量和西药组Wnt3蛋白显著增加(P<0.01)、TLTT高、中、低剂量和西药组β-catenin蛋白显著增加(P<0.01,P<0.05),TLTT高、中、低剂量和西药组GSK-3β蛋白显著增加(P<0.01,P<0.05),TTLTT高、中剂量和西药组Wif-1蛋白显著下降(P<0.01,P<0.05)。结论通络糖泰可在一定程度上减轻DPN坐骨神经损伤,其机制可能与激活制Wnt/β-catenin信号通路有关。

Non-Obese Type 2 Diabetic Rat Models-GK Rat and SDT Rat

The number of diabetic patients has recently been increasing all over the world together with lifestyle changes including sedentary life and high-calorie diet intake, and as a result the increase in these suffering from diabetes mellitus has become a global issue. Diabetic animal models play a key role in bettering our understanding of the pathophysiology of diabetes and in developing new therapies for the disease. Diabetes is classified into two types, type 1 and type 2, and type 2 diabetes is chiefly caused by a depletion of insulin secretion in the pancreas and insulin resistance in peripheral tissues. The Goto-Kakizaki (GK) rat and the Spontaneously Diabetic Torii (SDT) rat are genetic non-obese type 2 diabetic models, and the both rats are considered to be suitable models for investigating the etiology of the depletion of insulin secretion and impaired glucose tolerance. In this review, we overviewed the outline of pathophysiological features in GK rats and SDT rats, including biological parameters and pharmacological responses.

GK糖尿病大鼠感染创面的生物学特性研究

目的:建立GK大鼠全皮层切除合并感染模型,探讨其生物学特性改变,为GK大鼠应用于糖尿病足感染创面的治疗研究提供参考依据。方法:取SPF级的雄性GK大鼠和雄性Wistar大鼠,建立感染创面模型,于不同时间点对创面进行拍照后计算创面愈合率。在D1、D3、D7、D14和D21,对换下敷料进行细菌培养计数。在第D22,取大鼠清血和创面组织,用ELISA法测定血清中降钙素原(PCT)和超敏C⁃反应蛋白(hs⁃CRP)的含量,创面组织行HE染色观察组织病理学情况。结果:相对于Wistar大鼠,在D3、D7、D11、D14、D17时间点,GK大鼠的创面愈合率显著减少;在D7时间点,GK大鼠感染创面的纱布敷料菌落数显著增加。另外,GK大鼠血清中PCT、hs⁃CRP均显著增加。HE染色结果显示,GK大鼠创面的新生表皮较薄。结论:GK糖尿病大鼠感染创面是一种适用于糖尿病足感染治疗相关研究的动物模型。

参芪复方对GK大鼠炎症标志物的影响及机理探讨

目的:探讨参芪复方对2型糖尿病(type 2 d iabetes m ellitus,T2DM)炎症标志物的影响及作用机理。方法:设模型、雷米普利(1 mg/kg.d)、参芪复方低、高剂量(0.72 g/kg.d与2.88 g/kg.d)及W istar对照组,各组动物每天灌胃相应受试物32 d。酶免法检测血清C反-应蛋白(C-reactive prote in,CRP)、放免法检测血清肿瘤坏死因子(tumour necrosis factor,TNFα)-含量;实时定量RT-PCR和免疫组织化学法分别检测主动脉核因子(NF)κ-B p65mRNA的表达和活化。结果:参芪复方低、高剂量组CRP、TNFα-含量均显著低于模型组(P<0.05或P<0.01),NFκ-B p65表达与活化均降低(P<0.05或P<0.01)。结论:参芪复方具有降低T2DM血清炎症标志物水平的作用,减少NFκ-B基因的表达和活化可能是其作用机理之一。

参芪复方对GK大鼠脂代谢异常的实验研究

[目的]观察参芪复方对2型糖尿病(T2DM)脂代谢异常的影响并探讨其作用机制。[方法]按血糖值高低随机分为模型组,雷米普利组[0.45mg/(kg·d)],参芪复方低、高剂量组[0.504g/(kg·d)与2.002g/(kg·d)]及Wistar对照组,给药30d。用葡萄糖氧化酶法、酶免法及生化检测法等测定大鼠空腹血糖(FPG)、血清氧化修饰低密度脂蛋白(ox-LDL)、血脂及游离脂肪酸(FFA)。[结果]参芪复方高剂量组FPG、FFA、ox-LDL及血脂水平显著低于模型组(P<0.05或P<0.01)。[结论]参芪复方能够改善其血脂紊乱状态,并有一定降糖作用。

GK糖尿病大鼠生物学特性观察

目的了解2型糖尿病模型GK大鼠生长曲线、主要脏器重量、糖代谢等生物学特性，评价GK大鼠葡萄糖刺激的胰岛素分泌能力。方法采用51只雄性GK大鼠及15只年龄性别匹配的Wistar大鼠作为研究对象。测定13周龄GK、Wistar大鼠空腹血糖、23周龄GK大鼠空腹及随机血糖。随访GK及Wistar大鼠生长曲线，34～46周龄期间血糖、糖化血红蛋白。46周龄时行腹腔葡萄糖耐量实验（IPGTT），计算相关参数评价β细胞葡萄糖刺激的胰岛素分泌能力；之后处死大鼠，脏器称重。比较GK及Wistar大鼠间上述各指标差异。结果13周龄GK大鼠空腹血糖4．74±0．41mmol／L，对照Wistar大鼠1．85±0．44mmol／L（P〈0．001）。23周龄GK大鼠空腹血糖7．88±1．96mmol／L，随机血糖9．91±3．52～13．46±4．13mmol／L。7～20及34～45周龄期间GK大鼠体重高于对照Wistar大鼠（P〈0．05），46周龄时无显著性差异。34～45周龄期间GK大鼠空腹血糖、进食后血糖、HbAlc均高于对照Wistar大鼠（P〈0．05）。IPGTT曲线下面积分析示GK大鼠胰岛素曲线下面积（AUCi）、葡萄糖曲线下面积（AUCg）高于对照Wistar大鼠，胰岛素与葡萄糖曲线下面积比值（AUCi／AUCg）低于对照Wistar大鼠，差异均有显著性（P〈0．05）。GK大鼠肾脏重量高于对照Wistar大鼠（P〈0．05），余主要脏器重量差异无显著性。结论GK大鼠空腹血糖、进食后血糖、HbAlc水平升高，葡萄糖刺激的胰岛素分泌能力（GSIS）减退，葡萄糖刺激后胰岛素分泌早期相消失，晚期相代偿性增加，具有2型糖尿病特点；体重、血糖等生物学特性稳定。

高脂饮食对Wistar和GK大鼠糖脂代谢及胰岛素分泌功能的影响

目的观察高脂饮食对正常血糖Wistar大鼠和高血糖GK大鼠糖脂代谢及胰岛素分泌功能的影响。方法雄性Wistar和GK大鼠各20只,随机分为4组(n=10):Wistar普食组(WND),Wistar高脂组(WHD),GK普食组(GND)和GK高脂组(GHD)。分别以普通饲料和高脂饲料喂养12周,测定大鼠的糖脂代谢指标,并采用口服葡萄糖胰岛素释放试验评估胰岛素分泌能力。结果实验12周后,WHD和GHD组的内脏脂肪占体质量百分比分别显著高于WND和GND组,(8.20±0.50)%vs(6.00±0.60)%和(8.40±0.70)%vs(6.80±0.90)%(P均<0.01)。GHD组的空腹血糖(FPG)明显高于GND组,(12.85±1.44)vs(9.71±0.42)mmol/L(P<0.01);而WHD和WND组的FPG无显著差异。WHD和GHD组的胰岛素曲线下面积/葡萄糖曲线下面积分别显著小于WND和GND组,8.61±1.17vs11.26±1.37和0.95±0.11vs1.23±0.17(P均<0.01)。结论正常血糖和高血糖状态下,高脂饮食均可引起Wistar和GK大鼠中心型积聚的体脂增加,导致葡萄糖耐量和胰岛素分泌能力减退,为2型糖尿病进程中的重要危险因素。

黄芪乌梅配方颗粒对GK大鼠胰岛素抵抗的影响

目的观察黄芪乌梅配方颗粒对GK大鼠胰岛素抵抗的影响。方法 4周龄雄性GK大鼠32只,随机分为模型组、阳性对照组(盐酸二甲双胍肠溶片0.15g/kg)、黄芪乌梅低剂量组(黄芪乌梅配方颗粒1.3g/kg)、黄芪乌梅高剂量组(黄芪乌梅配方颗粒5.2g/kg),每组8只;同时以8只同周龄雄性Wistar大鼠为空白组。灌胃治疗10周,分别于0、2、4、6、8、10周测量大鼠体重、空腹血糖。干预第10周末取血,测量空腹血清胰岛素(FINS)和糖化血红蛋白(GHb)水平,计算胰岛素抵抗指数(HOMA-IR),然后急性失血法处死大鼠,取肝脏组织,蛋白印迹法检测肝脏胰岛素受体(IR)和胰岛素受体底物-1(IRS-1)蛋白的表达。结果干预10周后,空白组、模型组、阳性对照组大鼠体重差异无统计学意义(P>0.05),而各黄芪乌梅干预组大鼠体重明显减轻(P<0.05)。与空白组相比,模型组大鼠空腹血糖明显升高(P<0.05);与模型组相比,各黄芪乌梅干预组及阳性对照组大鼠空腹血糖明显降低(P<0.05)。与空白组相比,模型组大鼠FINS、GHb和HOMA-IR明显升高(P<0.05);与模型组相比,各黄芪乌梅干预组和阳性对照组大鼠HOMA-IR均降低(P<0.05),黄芪乌梅高剂量组和阳性对照组大鼠FINS、GHb降低(P<0.05)。与空白组相比,模型组IR和IRS-1蛋白表达明显下降(P<0.05);与模型组相比,各黄芪乌梅干预组及阳性对照组IR和IRS-1蛋白表达均明显增加(P<0.05)。结论黄芪乌梅配方颗粒能降低GK大鼠血糖,减轻体重,改善大鼠胰岛素抵抗,其机制可能与促进肝脏组织中IR和IRS-1蛋白表达有关。

中药复方糖耐康对糖尿病GK大鼠尿蛋白影响的实验研究

目的观察中药糖耐康对自发性糖尿病大鼠尿蛋白的影响。方法将50只GK大鼠随机分为模型对照组、吡格列酮组、中药糖耐康低、中、高剂量组,另设正常对照组Wistar大鼠10只。各治疗组大鼠干预8周后,检测肾重/体重、尿蛋白等指标,同时光镜下观察肾小球病理变化。结果糖尿病模型组各项实验室指标与正常对照组比较均有显著差异,而吡格列酮组和糖耐康各剂量组经过8周干预后各项指标有所改善。治疗组肾小球内细胞外基质蓄积、基底膜的增厚及肾小球系膜细胞增生指标均明显改善。结论中药糖耐康能降低血糖,控制尿蛋白的排泄,并通过抑制大鼠糖尿病肾小球系膜细胞增生、基底膜基质合成以及肾小球内细胞外基质蓄积,从而改善肾小球的高滤过和高灌注,对糖尿病大鼠肾脏具有保护作用。

参芪复方对GK大鼠白色脂肪组织脂联素基因表达的影响

目的:探讨参芪复方抗2型糖尿病低度炎症的作用机理。方法:SPF级GK大鼠按血糖水平随机分为模型、雷米普利、参芪复方低剂量与参芪复方高剂量组,另设正常Wistar对照组。4组GK大鼠和正常Wistar对照组分别腹腔注射L-N-硝基精氨酸甲酯(N-ω-nitro-L-arginine methyl ester,L-NAME)和生理盐水,同时喂饲高脂饲料和普通饲料。各组动物每天灌胃相应受试物和无菌水32 d。酶免法检测血清C反应蛋白(C reactive protein,CRP)和脂联素含量,实时定量RT-PCR法检测脂肪脂联素mRNA表达。结果:参芪复方低、高剂量组大鼠的血清CRP水平较模型组显著降低(P<0.01),脂联素mRNA表达和血清蛋白含量较模型组明显增加(P<0.05或P<0.01)。结论:提高脂联素mRNA表达和血清蛋白水平可能是参芪复方抗T2DM低度炎症的作用机制之一。

黄地安消胶囊对改善2型糖尿病GK大鼠胰岛素抵抗的影响

目的观察黄地安消胶囊(葛根、枇杷叶、三七,等)对2型糖尿病(T2DM)模型GK大鼠的血糖和胰岛素抵抗的影响及可能的效应机制。方法选取符合T2DM模型的GK大鼠纳入实验,随机分为模型组,罗格列酮(1.44 mg/kg)组,参芪降糖颗粒(1.08 g/kg)组,黄地安消胶囊高、中、低(12、6、3 g/kg)组以及Wistar大鼠正常组。各组连续给药6周后,测定各组大鼠的空腹血糖(FBG)、血清胰岛素(FINS)含有量、空腹血清血糖(FPG),并计算胰岛素抵抗指数(HOMA-IR)。对血清生化指标(TG、TC、HDL-C、LDL-C)、糖化血红蛋白(Hb A1c)、胰高血糖素样肽-1(GLP-1)及胰岛素样生长因子(IGF-1)进行测定。取胰腺组织,常规石蜡包埋并进行HE染色,观察其病理形态的改变。结果与正常组比较,模型组FBG、FPG、FINS、HOMA-IR、TG、TC、HDL-C、LDL-C、Hb A1c均显著升高(P<0.01),GLP-1、IGF-1表达量显著降低(P<0.01)。与模型组比较,黄地安消高、中、低剂量组FBG、FPG、FINS、HOMA-IR、TG、TC、HDL-C、LDL-C、Hb A1c均明显降低(P<0.05,P<0.01);GLP-1、IGF-1表达量显著增加(P<0.05,P<0.01),黄地安消高、中、低剂量组胰腺组织结构改变明显减轻。结论黄地安消胶囊能够降低GK大鼠空腹血糖,改善胰岛素抵抗,其机制可能与促进胰岛细胞的产生与增殖,改善胰岛细胞的功能,增加胰岛素的分泌有关。

参芪复方对GK大鼠肾NF-κBmRNA表达的影响

目的观察参芪复方对GK大鼠肾核转录因子κBmRNA(NF-κBmRNA)表达的影响及其可能的作用机制。方法将随机血糖≥11.1 mmol.L-1的GK大鼠40只随机分为雷米普利组、参芪复方高剂量组、参芪复方低剂量组、模型组等4组,设正常SD大鼠10只为空白组。灌胃8周后,取大鼠右肾,以RT-PCR法测定各组大鼠肾组织NF-κBmRNA表达的变化。结果参芪复方高剂量组GK大鼠肾NF-κBmRNA表达下降,和模型组比较有统计学意义(P<0.05)。结论参芪复方高剂量能够抑制NF-κBmRNA表达,可能是其防治糖尿病肾病(DN)的作用机制之一。

2型糖尿病GK大鼠胰岛β细胞凋亡的研究

目的研究2型糖尿病GK大鼠胰岛β细胞凋亡可能机制。方法选择10周龄雄性GK大鼠为2型糖尿病大鼠模型,同源雄性Wistar大鼠为对照组,均以普通饲料喂养12周,定期行OGTT、血脂、空腹胰岛素测定。12周后处死大鼠,光镜下HE染色观察胰岛结构,电镜观察大鼠胰腺组织超微结构的改变,免疫组化法检测胰腺组织Bcl-2及Bax蛋白的表达,TUNEL法检测胰腺组织的β细胞凋亡数。结果与Wistar大鼠比较,GK大鼠血糖呈轻、中度升高(P<0.05),尤以餐后血糖升高明显;血清总胆固醇、低密度脂蛋白升高(P<0.01),血清甘油三酯降低(P<0.05),血清高密度脂蛋白无明显变化(P>0.05),血浆胰岛素水平升高(P<0.01)。透射电镜观察Wistar大鼠的胰岛结构完整,GK大鼠胰岛β细胞呈现凋亡早期改变。GK大鼠Bcl-2蛋白表达低于Wistar大鼠(P<0.05),Bax蛋白表达高于Wistar大鼠(P<0.01),β细胞凋亡数高于Wistar大鼠(P<0.01)。结论 GK大鼠早期即可呈现胰岛β细胞凋亡,凋亡相关基因Bcl家族成员间的失衡是导致GK大鼠胰岛β细胞凋亡的可能机制之一。

参芪复方对GK大鼠2型糖尿病大血管病变CD36 mRNA及ox-LDL的影响

目的观察参芪复方对GK大鼠2型糖尿病大血管病变胸主动脉CD36 mRNA表达及血清ox-LDL的影响。方法SPF级GK大鼠(自发性糖尿病大鼠)44只及Wistar大鼠11只按血糖水平随机分为正常对照组、模型组、雷米普利组、参芪复方低剂量组、参芪复方高剂量组。4组GK大鼠组造模:10 mg.kg-1.d-1腹腔注射N-硝基-L-精氨酸甲酯(L-NAME),同时给高脂饮食,连续14 d造模。正常对照组给生理盐水。2周后开始给药,各组分别给相应受试药物28天。用ELISA法测ox-LDL,用实时定量PCR法测胸主动脉CD-36 mRNA表达。结果参芪复方高、低剂量组的血清ox-LDL含量较模型组明显降低(P<0.05),胸主动脉CD36 mRNA的表达显著低于模型组组(P<0.01),血清ox-LDL含量与胸主动脉CD36 mRNA的C t值进行相关性分析,相关系数r=-0.60,P<0.01。结论以益气养阴、清热生津、活血化瘀为治则的参芪复方能明显下调GK大鼠内皮细胞损伤的CD36 mRNA的表达,抑制CD36的生成,可以阻断CD36对ox-LDL的摄取,可能是参芪复方治疗T2DM大血管病变的机制之一。

参芪复方对GK大鼠心肌细胞凋亡相关因子Bcl-2、Bax及NO的影响

[目的]研究参芪复方对GK大鼠心肌细胞凋亡相关因子Bcl-2、Bax及一氧化氮(NO)的影响及其可能作用机制。[方法]GK大鼠腹腔注射N-硝基-L-精氨酸甲酯(L-NAME),同时给予高脂饮食复制2型糖尿病(T2DM)心肌病变模型。选择随机血糖≥11.1mmol/L的GK大鼠随机分为4组:模型组、中药高、低剂量组、西药组,另设正常Wistar大鼠作正常对照组,共5组动物。治疗4周后,统一取心肌标本,通过免疫组化等测量方法,对照观察各组药物对GK大鼠一般状态、心肌NO、心肌Bcl-2、Bax蛋白表达的影响。[结果]GK大鼠的上述指标存在明显异常。参芪复方特别是其高剂量组能改善其一般状态、升高心肌NO(P<0.01),升高心肌细胞凋亡抑制因子Bcl-2的表达(P<0.01),降低促细胞凋亡因子Bax表达(P<0.05)和Bax/Bcl-2比值(P<0.01)。[结论]凋亡相关因子Bcl-2和Bax与NO参与糖尿病心肌损伤过程,参芪复方能升高心肌NO,降低心肌Bax表达,升高Bcl-2表达。

小檗碱甘草酸络盐对GK大鼠的抗糖尿病作用

目的:研究小檗碱甘草酸络盐(BGC)的抗糖尿病作用。方法:4月龄GK大鼠随机分为5组,模型对照组、阳性对照组、低剂量给药组、中剂量给药组和高剂量给药组,另取Wisar大鼠10只作为正常对照组;各组大鼠分别每日ig BGC、小檗碱或生理盐水共6周,给药4周后测空腹血糖和餐后血糖。6周后取血测血脂(TG、TC、HDL-c、LDL-c)、MDA、FFA、糖化血清蛋白、胰岛素水平;取肾、胰组织作病理切片。结果:与模型组相比,GK大鼠给药组餐后血糖下降,糖化血清蛋白和胰岛素水平降低,血清LDL和MDA降低;GK大鼠肾脏、胰腺的组织形态学病变改善。结论:BGC具有抗糖尿病作用。