脂蛋白脂酶基因敲除鼠的脂代谢研究

目的通过野生型(c57)小鼠及脂蛋白脂酶(LPL)基因敲除杂合子(LPL+/-)小鼠体内实验,探讨LPL对小鼠体质量、脂肪及血脂等方面的影响。方法对LPL+/-小鼠和c57小鼠行表型鉴定后,分为两组,每组6只,比较两组小鼠在体质量,脂肪含量及血脂等方面的变化。结果LPL+/-小鼠甘油三酯(TG)、游离脂肪酸(FFA)、体质量及内脏脂肪含量均较c57小鼠高(P<0.05),而其肝脏、骨骼肌、脂肪及胰腺组织的TG、FFA较c57小鼠也呈现不同程度的增高趋势,其中肝脏TG的增高差异有统计学意义(P<0.05)。结论小鼠体内实验证实了LPL基因敲除可导致体质量,脂肪含量的增加,同时引起FFA的增高及高TG血症,以及组织血脂水平不同程度的增高趋势。     

小鼠代谢综合征模型的特征及西布曲明的治疗作用研究

目的研究高脂饲料诱导C57BL/6 J小鼠形成代谢综合征(MS)模型的特点,以及盐酸西布曲明对MS小鼠的治疗作用。方法用含10%猪油、2%胆固醇及0.4%胆酸钠的高脂饲料喂养9 wk♂C57BL/6 J小鼠18.5 wk,然后用西布曲明8 mg.kg-1灌胃10 d。实验终点时测定体重、腹腔内脏脂肪及肝脏湿重和肝游离脂肪酸(FFA)含量;取血分离血清测定血脂、血糖和血清胰岛素水平,并计算胰岛素抵抗指数;肝组织进行HE染色和油红O染色,光镜下观察脂肪病变程度。结果模型组小鼠脂肪重量及系数、肝脏重量均明显升高,肝组织切片光镜下可见明显的脂肪病变;血总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)及低密度脂蛋白胆固醇(LDL-C)水平均升高,且以LDL-C升高最为明显;高胆固醇喂养使模型小鼠血甘油三酯(TG)水平降低。西布曲明可改善MS小鼠的中心性肥胖、高血糖、高胰岛素血症和胰岛素抵抗,并进一步降低MS小鼠的血TG水平;但是,西布曲明可增加肝FFA含量,对MS小鼠的肝脏湿重及肝脂肪病变无改善作用。结论高脂饲料长期喂养C57小鼠可成功建立类似人类MS表现的动物模型;西布曲明可改善MS小鼠的中心性肥胖、糖脂代谢异常、增加机体对胰岛素的敏感性,对MS有一定的治疗作用。     

氧化苦参碱对高脂诱导胰岛素抵抗ApoE~(-/-)小鼠肝脏脂代谢相关基因的影响

目的探讨氧化苦参碱对高脂诱导胰岛素抵抗Apo E~(-/-)小鼠肝脂代谢相关基因的影响。方法 17只♂C57BL/6J小鼠作为对照组,给予正常饮食;68只♂Apo E~(-/-)小鼠,给予高脂饮食,饲养16周后,将小鼠分为模型组、氧化苦参碱低、中、高剂量组。给药8周,测定小鼠体重和一般生化指标。荧光定量PCR和Western blot方法检测肝组织LPL、FAT/CD36、CPT1、UCP2、SREBP-1c、FAS、ACC m RNA和蛋白表达水平。结果氧化苦参碱能不同程度的降低体重、FBG、TC、TG、FFA、FINS、HOMA-IR,升高GIR,改善胰岛素的抵抗。同时降低了LPL、FAT/CD36、UCP2、SREBP-1c、FAS、ACC m RNA和蛋白的表达水平,升高了CPT1表达水平。结论氧化苦参碱能够通过脂转运、氧化、合成3个环节较全面的调节肝脂质代谢,改善高脂诱导的Apo E~(-/-)小鼠的胰岛素抵抗。     

肿瘤坏死因子α致小鼠肝甘油三酯蓄积的作用

目的探讨肿瘤坏死因子α(TNF-α)对小鼠肝甘油三酯(TG)含量的影响及机制。方法 SPF级雄性ICR小鼠,随机分为对照组和TNF-α干预组。TNF-α干预组小鼠腹腔注射0.166 mg/kg·bw TNF-α,对照组小鼠给予等体积的生理盐水。在给药后3和6 h,各组分别处死6只小鼠,收集血清、肝和附睾脂肪,计算肝脏系数和附睾脂肪系数;油红O染色观察肝冰冻切片中脂肪蓄积;检测肝TG含量、血清中游离脂肪酸(FFA)和TG含量及转氨酶的活性;Western blot检测肝脂肪代谢相关蛋白和附睾脂肪激素敏感性脂肪酶(HSL)的蛋白含量。结果与对照组小鼠相比,TNF-α干预组小鼠肝脏系数在3和6 h均明显增加,差异有统计学意义(P0.05);TNF-α干预组小鼠附睾脂肪系数呈减小趋势。在6 h时间点,TNF-α干预组小鼠肝TG含量明显增加,差异有统计学意义(P0.05)。在3 h时间点,TNF-α干预组小鼠血清FFA水平明显增加(P0.05);TNF-α干预组小鼠附睾脂肪中p-HSL~((Ser563))蛋白含量较对照组小鼠明显增加(P0.05)。在3和6 h两个时间点,肝内过氧化物酶体增殖物活化受体α(PPAR-α)、乙酰辅酶A氧化酶(ACOX1)、甾醇调节元件结合蛋白1c(SREBP-1c)及脂肪酸合成酶(FAS)的蛋白含量在两组小鼠之间差异均无统计学意义(P0.05)。结论 TNF-α可导致小鼠肝TG含量增加,其机制可能与磷酸化激活HSL进而促进外周脂肪动员有关。     

孕期LPS刺激对子代6周龄大鼠血管结构的影响

目的研究孕期炎症刺激剂脂多糖(lipopolysaccharides,LPS)刺激对子代大鼠6周龄时血管结构的影响。方法 12只Sprague dawley(SD)孕鼠随机分为3组:对照组(control,Con)、LPS刺激组、LPS刺激加二硫代氨基四氢呋喃(pyrrolidinedithiocarbamate,PDTC)干预组(L+P),分别在孕8~14 d腹腔注射生理盐水、LPS(0.79 mg·kg~(-1))或LPS加PDTC(100 mg·kg~(-1)),LPS于孕d 8、10、12给药;生理盐水及PDTC于d 8~14每天给药。子代出生6周测体质量;透射电镜观察血管超微结构;实时荧光定量PCR检测仔鼠胸主动脉连接蛋白(connexin,Cx)Cx37、Cx40、Cx43、Cx45的mRNA表达水平;Western blot和免疫荧光检测仔鼠胸主动脉Cx37、Cx40、Cx43、Cx45的蛋白表达水平。结果与Con组相比,LPS组子代大鼠在6周时♂♀体质量均明显增加(P<0.01);L+P组♂鼠明显低于LPS组(P<0.05),而♀鼠差异无显著性。LPS组内皮受损,内皮细胞间可见明显缝隙连接(gap junction,GJ),相对于Con组较长且多见;L+P组内皮损伤程度较LPS组稍有改善。LPS组Cx43 mRNA及蛋白表达均明显低于Con组(P<0.05),L+P组则明显高于LPS组(P<0.05);Cx37、Cx40和Cx45各组间mRNA及蛋白表达差异无统计学意义。LPS组Cx43荧光强度及荧光点数明显比Con组降低,而L+P组明显比LPS组高,各组间Cx37、Cx40和Cx45荧光强度和荧光点数并无明显差异。结论孕期LPS刺激可致子代大鼠在6周龄时出现血管结构损伤,这种损伤可能持续于新生儿期,并与其成年发生高血压密切相关。     

奥贝胆酸对MCD饮食诱导的非酒精性脂肪性肝炎小鼠血清脂质与胆汁酸以及肠道菌群的调节作用

肠-肝轴在非酒精性脂肪性肝病的发生、发展与消退中具有重要调控作用,奥贝胆酸(obeticholic acid,OCA)是法尼酯X受体激动剂。本文用蛋氨酸和胆碱缺乏(methionine and choline deficient, MCD)饮食喂养C57BL/6小鼠8周,同时灌胃OCA (6.5 mg·kg-1·d-1),应用UPLC-MS技术及16S rDNA测序技术研究了OCA对MCD小鼠血清脂质与胆汁酸代谢组学,以及小鼠回肠菌群组成的影响。结果表明:OCA降低了MCD小鼠血清谷氨酸氨基转移酶(alanine aminotransferase, ALT)、天门冬氨酸氨基转移酶(aspartate aminotransferase, AST)活性和肝脏甘油三酯(triglyceride, TG)、丙二醛(malondialdehyde, MDA)含量,缓解了肝脂堆积与炎症; OCA下调了血清中2个类花生酸(12,13-EpOME、9,10-EpOME)、4个游离脂肪酸(free fatty acid, FFA)(FFA16∶1、FFA18∶1、FFA16∶2、FFA18∶3)和TG(...     

2型糖尿病中游离脂肪酸与胰岛素抵抗的关系

2型糖尿病患者表现为胰岛素抵抗，即患者胰岛素p细胞对胰岛素不敏感。胰岛p细胞的功能减退是发病的关键。2型糖尿病患者多数伴肥胖，而肥胖本身可导致一定程度的胰岛素抵抗。游离脂肪酸(FFA)是联系肥胖和胰岛素抵抗或高胰岛素血症的重要环节。肥胖患者的脂肪组织摄取葡萄糖及从血浆中移除甘油三酯(tridyceride，TG)减少，但是脂蛋白脂肪酶活性     

海带多糖对高脂血症小鼠血脂和瘦素水平的影响

目的探讨海带多糖对高脂血症小鼠模型血脂和瘦素水平的影响及其可能的机制。方法雄性昆明小鼠64只,随机分为对照组、模型组和海带多糖(低、中、高剂量)治疗组。应用高脂饮食喂养4周后建立高脂血症动物模型,海带多糖(1500、3000、6000mg·kg-1)灌胃干预治疗。应用酶法及胆固醇氧化法测定血清中甘油三酯(TG)、总胆固醇(TC)含量,ELISA法测定血清游离脂肪酸(FFA)、瘦素(Leptin)含量。结果高脂模型组小鼠血清TG、TC、FFA、Leptin含量明显高于对照组(P<0.01)。海带多糖高、中、低剂量组小鼠血清TG、TC、Leptin含量较模型组显著降低(P<0.05),中、高剂量组血FFA含量明显低于模型组(P<0.01)。结论海带多糖可显著降低高脂血症小鼠血脂水平,改善瘦素抵抗。     

雷诺嗪对高脂高糖诱导的胰岛β细胞NIT-1功能损伤的保护作用

目的 观察雷诺嗪对高糖高脂诱导的胰岛β细胞NIT-1三酰甘油(TG)含量及脂肪酸转位酶(FAT/CD36)表达的增加和胰岛素分泌功能损伤的保护作用. 方法 用放免法检测高糖高脂及5 μmol.L^-1雷诺嗪共同作用后细胞基础胰岛素分泌(BIS)和葡萄糖刺激后胰岛素分泌(GSIS)水平的变化,酶法检测胞内TG含量,Western blot检测细胞FAT/CD36蛋白的表达. 结果正常组、高糖高脂组和雷诺嗪组的胞内TG含量分别为(2.31±0.05),(5.17±0.03)和(3.63±0.01) mmol.L^-1;BIS分别为(0.67±0.03),(0.32±0.07),(0.51±0.03)ng.mL^-1,GSIS分别为(1.68±0.17),(1.35±0.08),(1.47±0.11)ng.mL-1;FAT/CD36的相对表达量比值A1分别为(0.53±0.08),(1.78±0.05)和(1.07±0.06). 与正常组比较,高糖高脂组GSIS降低,细胞内TG含量增多. FAT/CD36蛋白表达显著增加(P<0.05). 而雷诺嗪与高糖高脂的共同作用24 h后可以显著升高GSIS,同时降低胞内TG含量,减少FAT/CD36蛋白. 结论 雷诺嗪对高糖高脂导致的胰岛细胞NIT-1分泌功能损伤有保护作用,同时可以减少胞内脂质沉积,其分子机制可能是通过脂肪酸转位酶FAT/CD36蛋白表达的改变.     

二甲双胍对大鼠非酒精性脂肪性肝炎的防治作用

目的:研究二甲双胍对大鼠非酒精性脂肪性肝炎(NASH)的防治作用。方法:取SD大鼠40只随机分为4组(n=10),即对照组、模型组、烟酸组及二甲双胍组。除对照组外,其余各组分别每天给予脂肪乳剂、烟酸、二甲双胍。实验开始1周后断尾取血,测定血清脂质;3周后处死大鼠,测定血清三酰甘油(TG)、总胆固醇(TC)、丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、游离脂肪酸(FFA)、空腹血糖(FBG)、肿瘤坏死因子-α(TNF-α)和肝匀浆TG、TC、FFA水平,并行肝脏病理学检查。结果:与模型组比较,二甲双胍组能降低大鼠血清TG、ALT、FFA、FBG、TNF-α水平及肝匀浆中TG、FFA水平和肝脂肪变性程度及炎症水平(P<0.05或P<0.01)。结论:二甲双胍对脂肪乳剂诱导的NASH模型大鼠具有防治作用。     

Quantitative in vivo and in vitro sex differences in artemisinin metabolism in rat

1. The pharmacokinetics of the antimalarial compound artemisinin were compared in the male and female Sprague-Dawley rat after single dose i.v. (20 mg.kg) or i.p. (50 mg.kg) administration of an emulsion formulation. 2. Plasma clearance of artemisinin was 12.0 (95% confidence interval: 10.4, 13.0) l.h. kg in the male rat and 10.6 (95% CI: 7.5, 15.0) l.h. kg in the female rat suggesting high hepatic extraction in combination with erythrocyte uptake or clearance. Artemisinin half-life was 0.5 h after both routes of administration in both sexes. Values for plasma clearance and half-lives did not statistically differ between the sexes. 3. After i.p. administration artemisinin AUCs were 2-fold higher in the female compared with male rat (p 0.001). Artemisinin disappearance was 3.9-fold greater in microsomes from male compared with female livers and it was inhibited in male microsomes by goat or rabbit serum containing antibodies against CYP2C11 and CYP3A2 but not CYP2B1 or CYP2E1. 4. The unbound fraction of artemisinin in plasma was lower (p 0.001) in plasma obtained from the male (8.8 2.0%) compared with the female rat (11.7 2.2%). 5. The possibility of a marked sex difference, dependent on the route of administration, has to be taken into account in the design and interpretation of toxicological studies of artemisinin in this species.     

Quantitative in vivo and in vitro sex differences in artemisinin metabolism in rat

1. The pharmacokinetics of the antimalarial compound artemisinin were compared in the male and female Sprague-Dawley rat after single dose i.v. (20 mg x kg(-1)) or i.p. (50 mg x kg(-1)) administration of an emulsion formulation. 2. Plasma clearance of artemisinin was 12.0 (95% confidence interval: 10.4, 13.0) 1 x h(-1) x kg(-1) in the male rat and 10.6 (95% CI: 7.5, 15.0) 1 x h(-1) x kg(-1) in the female rat suggesting high hepatic extraction in combination with erythrocyte uptake or clearance. Artemisinin half-life was approximately 0.5 h after both routes of administration in both sexes. Values for plasma clearance and half-lives did not statistically differ between the sexes. 3. After i.p. administration artemisinin AUCs were 2-fold higher in the female compared with male rat (p < 0.001). Artemisinin disappearance was 3.9-fold greater in microsomes from male compared with female livers and it was inhibited in male microsomes by goat or rabbit serum containing antibodies against CYP2C11 and CYP3A2 but not CYP2B1 or CYP2E1. 4. The unbound fraction of artemisinin in plasma was lower (p < 0.001) in plasma obtained from the male (8.8 +/- 2.0%) compared with the female rat (11.7 +/- 2.2%). 5. The possibility of a marked sex difference, dependent on the route of administration, has to be taken into account in the design and interpretation of toxicological studies of artemisinin in this species.     

Interindividual variability in metabolic activation in humans in vivo

In assessing interindividual variability in metabolic activation, the toxic metabolite is often too unstable for conventional analysis. Possible alternatives include a stable product of the reactive metabolite e.g. cysteinyl derivatives of N-acetyl-4-benzoquinoneimine, the toxic metabolite of paracetamol, adducts with DNA or protein, and indirect measurement of the activity of the enzyme(s) producing the active metabolite. An example of the last approach is the use of furafylline, a highly specific inhibitor of human CYP1A2, to determine the extent of the metabolic activation of the cooked food mutagens PhIP and MeIQx. The extent of inhibition, determined from levels of unchanged amine in urine, is an indirect measure of the activity of the activation pathway. Further refinement of this approach, allied to improved measures of the biological process of interest should prove of value in evaluating interindividual variability and its role in the risk assessment process.     

Theophylline kinetics in peripheral tissues in vivo in humans

Several biochemical and cellular effects have been described for methylxanthines under in vitro conditions. However, it is unknown, whether threshold concentrations required to exert these effects are attained in target tissues in vivo. We therefore employed the microdialysis technique for measuring theophylline concentrations in peripheral tissues under in vivo conditions.Following in vitro and in vivo calibration, microdialysis probes were inserted into the medial vastus muscle and into the periumbilical subcutaneous adipose layer of healthy volunteers. Following single oral dose administration of 300 mg or i.v. infusion of 240 mg theophylline, in vivo time courses of theophylline concentrations were monitored in tissues and plasma. Major pharmacokinetic parameters (c_max, t_max, AUC) were calculated for plasma and tissue time courses. The mean AUC_tissue /AUC_plasma-ratio was 0.56 (p.o.) and 0.55 (i.v.) for muscle and 0.55 (p.o.) and 0.72 (i.v.) for subcutaneous adipose tissue.We conclude that microdialysis provides important information on the distribution and the tissue pharmacokinetics of theophylline.Abbreviations FPIA Fluorescence polarisation immuno assay - AUC Area under the curve - t_max Time to peak concentration - c_max Peak concentration     

休克时血中氧自由基的变化

本实验测定10名休克患者血浆和红细胞的丙二醛(MDA)、血浆总抗的氧化活性(AOA)的含量。结果表明:休克病人红细胞膜和血浆 MDA 含量(4.298±0.722;5.348±0.834)与对照组(3.235±0.682;4.356±1.081)比较明显增高(P<0.05);血浆 AOA(39.65±7.858)与对照组(48.21±10.81)比较明显降低(P<0.01)。提示:休克时,患者机体内自由基反应增强是引起组织细胞损伤的原因之一。     

Changes in angiopoietin expression in glomeruli involved in glomerulosclerosis in rats with daunorubicin-induced nephrosis

AIM: To study the potential pathological role of endogenous angiopoietins in daunorubicin-induced progressive glomerulosclerosis in rats. METHODS: Seventy male Wistar rats were allocated randomly into a daunorubicin group (DRB; n=40) or a control group (n=30). The rats in the DRB group were injected with DRB (15 mg/kg), in their tails. Subsequently, at intervals of 1, 2, 4, 6, 8, and 12 weeks, 5 male Wistar rats in each group were chosen randomly for 24 h urinary protein quantitative measurements (24 h UPQM), and determination of plasma tumor necrosis factor alpha (TNF-alpha), angiopoietin-1 (Ang1), and angiopoietin-2 (Ang2) levels. Kidney sections were examined by electron microscopy, Periodic Acid Schiff (PAS) staining, immunohistochemical staining and in situ hybridization histochemistry. RESULTS: As glomerulosclerosis progressed in the DRB group, expression of Ang1 mRNA and protein in glomeruli decreased and expression of TNF-alpha protein, Ang2 mRNA and protein in glomeruli increased. Expression of Ang1 mRNA and protein in glomeruli were negatively correlated with 24 h UPQM, Fn protein expression, and mean area of extracellular matrix (MAECM). In comparison, expression of Ang2 mRNA and protein in glomeruli were positively correlated with 24 h UPQM, Fn protein expression and MAECM; furthermore, there was a positive correlation between plasma Ang2 and 24 h UPQM. Plasma TNF-alpha and expression of TNF-alpha in glomeruli were positively correlated with expression of Ang2 mRNA and protein in glomeruli. There was a negative correlation between Ang1 protein expression and Ang2 protein expression in glomeruli. CONCLUSION: During DRB-induced glomerulosclerosis, podocyte injury led to a shift in the balance of Ang1 and Ang2 in glomeruli. Increased TNF-alpha in plasma and glomeruli may upregulate Ang2 expression in glomeruli. Elevated Ang2 in both plasma and glomeruli may mediate protein permeability through the glomerular filtration barrier. Moreover, local expression of Ang2 may facilitate the progress of glomerulosclerosis by upregulating a component expression of extracellular matrix.     

Trichinellosis in immigrants in Switzerland

We describe a case of trichinellosis diagnosed at the Division of Infectious Diseases, Hospital of Lugano, in January 2009. This case was associated with a cluster of cases and was traced to the consumption of contaminated meat after a wild boar hunt in Bosnia.