• 【尽管DEC1上调,但低氧治疗仍能抑制胰岛素诱导的ATDC5细胞软骨形成。】 复制标题 收藏 收藏
    DOI:10.1080/03008200600609558 复制DOI
    作者列表:Chen L,Fink T,Ebbesen P,Zachar V
    BACKGROUND & AIMS: :Chondrogenesis occurs in vivo in a hypoxic environment, in which the hypoxia inducible factor 1, HIF-1, plays a regulatory role, possibly mediated through the transcription factor DEC1. We have analyzed the effect of hypoxia (1% oxygen) alone and in combination with insulin on the chondrogenic differentiation of the mouse embryonic stem cell line ATDC5. Hypoxic treatment alone induced early chondrogenesis as evidenced by enhanced expression of aggrecan and collagen II, whereas hypoxic incubation of insulin-treated cells delayed and suppressed insulin-mediated early chondrogenesis and almost completely blocked hypertrophic differentiation. Paradoxically, the transcriptional activation of DEC1 was invariably enhanced by the hypoxic exposure.
    背景与目标: :软骨形成发生在体内低氧环境中,在该环境中,缺氧诱导因子1(HIF-1)发挥调节作用,可能是通过转录因子DEC1介导的。我们已经分析了单独和与胰岛素联合使用低氧(1%氧气)对小鼠胚胎干细胞系ATDC5软骨分化的影响。单用低氧治疗可诱导早期软骨形成,聚集蛋白聚糖和胶原II的表达增强证明了这一点,而对胰岛素处理的细胞进行低氧培养可延迟并抑制胰岛素介导的早期软骨形成,并且几乎完全阻断了肥大细胞的分化。矛盾的是,低氧暴露总是增强了DEC1的转录激活。
  • 【生长激素的遗传疾病-胰岛素样生长因子-I轴。】 复制标题 收藏 收藏
    DOI:10.1159/000095161 复制DOI
    作者列表:Walenkamp MJ,Wit JM
    BACKGROUND & AIMS: :In the last few years, our knowledge of genetically determined causes of short stature has greatly increased by reports of challenging patients, who offered the opportunity to study genes that play a role in growth. Since the first paper that showed the etiology of Laron syndrome [Godowski PJ, et al: Proc Natl Acad Sci USA 1989;86:8083-8087], many mutations in the growth hormone (GH) receptor have been identified. Recently, new mutations or deletions have been found in several components of the GH-insulin-like growth factor-I (IGF-I) axis: a homozygous mutation of the GH1 gene, resulting in a bio-inactive GH; mutations in the STAT5b gene, which plays a major role in the GH signal transduction; a homozygous missense mutation in the IGF-I gene; heterozygous mutations in the IGF-I receptor gene and a homozygous deletion of the acid-labile subunit gene. In this mini review, we describe the clinical and biochemical features of these genetic defects. Genetic analysis has become essential in the diagnostic workup of a patient with short stature. However, regarding the time consuming nature of molecular analysis, it is important to carefully select the patient for specific genetic evaluation. To help in this selection process, we developed flowcharts, based on the recently described patients, that can be used as guidelines in the diagnostic process of patients with severe short stature of unknown origin.
    背景与目标: :在过去的几年中,由于对挑战性患者的报道,我们对遗传决定的矮小身高原因的了解大大增加了,这些患者为研究在生长中起作用的基因提供了机会。自从第一篇显示Laron综合征病因的论文[Godowski PJ等人:Proc Natl Acad Sci USA 1989; 86:8083-8087]以来,已经确定了生长激素(GH)受体的许多突变。最近,在GH-胰岛素样生长因子-I(IGF-I)轴的几个组成部分中发现了新的突变或缺失:GH1基因的纯合突变,导致了生物失活的GH; STAT5b基因的突变,在GH信号转导中起主要作用; IGF-I基因的纯合错义突变; IGF-1受体基因中的杂合突变和对酸不稳定的亚基基因的纯合缺失。在这个小型综述中,我们描述了这些遗传缺陷的临床和生化特征。遗传分析已成为身材矮小的患者的诊断检查中必不可少的。但是,考虑到分子分析的耗时性质,重要的是要仔细选择患者进行特定的基因评估。为了帮助选择过程,我们根据最近描述的患者制定了流程图,可以将其用作诊断患有严重身材矮小,来源不明的患者的诊断过程中的指导原则。
  • 【辅助生殖后出生的儿童的血清胰岛素样生长因子-I(IGF-I)和生长。】 复制标题 收藏 收藏
    DOI:10.1210/jc.2006-0701 复制DOI
    作者列表:Kai CM,Main KM,Andersen AN,Loft A,Chellakooty M,Skakkebaek NE,Juul A
    BACKGROUND & AIMS: CONTEXT:Concern has been raised about the safety of assisted reproduction techniques for the offspring. OBJECTIVES:The objective of the study was to investigate postnatal growth and growth factors in children born after intra-cytoplasmatic sperm injection (ICSI) and in vitro fertilization (IVF). DESIGN:The study had two cohorts: a population-based longitudinal infant cohort 0-36 months [236 ICSI, 173 IVF, 1530 naturally conceived (NC)], and a cross-sectional child cohort at 5 yr (68 ICSI, 67 IVF, 70 NC). INTERVENTION:Anthropometrical measurements were made at birth, 3, 18, 36 (infant cohort), and 60 months (child cohort), and blood samples were collected at 3 or 60 months. MAIN OUTCOME MEASURES:Serum IGF-I, IGFBP-3, height, weight, head and abdominal circumference, body mass index, and fat folds were the main outcome measures. RESULTS:Anthropometrical measurements showed no significant differences between ICSI and IVF children and controls in either cohort. However, singleton ICSI girls [3.4 (0.6) kg, P = 0.008] had a slightly lower birth weight than IVF [3.5 (0.5) kg] and NC girls [3.5 (0.5) kg]. Birth weights of singleton boys [3.6 (0.5) kg], twin boys [2.6 (0.6) kg], and twin girls [2.4 (0.5) kg] did not differ between types of conception. In the infant cohort in 3-month-old singletons, serum IGF-I was lower in ICSI [78 (26) ng/ml] than NC boys [94 (27) ng/ml, P < 0.001] and IVF [74 (34) ng/ml], compared with NC girls [93 (43) ng/ml, P = 0.011]. ICSI children were also smaller than their target height (sd score) at 3 yr of age [mean -0.91 (1.2)], compared with NC children [-0.61 (0.9), P = 0.033]. In the child cohort, target height attainment (sd score) and growth factors did not differ among the three groups. CONCLUSIONS:The overall growth pattern of ICSI and IVF children in both cohorts was normal. Our findings of subtle differences in target height attainment and serum IGF-I levels between infants born after assisted reproduction techniques and controls may not be clinically significant. However, these observations indicate that further systematic follow-up of growth and puberty in these children is needed.
    背景与目标: 背景:人们对后代辅助生殖技术的安全性表示关注。
    目的:本研究的目的是调查胞浆内精子注射(ICSI)和体外受精(IVF)后出生的儿童的出生后生长和生长因子。
    设计:该研究有两个队列:基于人群的纵向婴儿队列0-36个月[236 ICSI,173 IVF,1530自然受孕(NC)]和5岁时的横断面儿童队列(68 ICSI,67 IVF ,70 NC)。
    干预措施:分别在出生时,3、18、36(婴儿队列)和60个月(儿童队列)进行人体测量,并在3或60个月时采集血样。
    主要观察指标:血清IGF-I,IGFBP-3,身高,体重,头围和腹围,体重指数和脂肪褶皱是主要的观察指标。
    结果:人体测量结果显示,ICSI和IVF儿童与对照组之间均无显着差异。但是,单身ICSI女孩[3.4(0.6)千克,P = 0.008]的出生体重略低于IVF [3.5(0.5)千克]和NC女孩[3.5(0.5)千克]。单胎男孩[3.6(0.5)千克],双胞胎男孩[2.6(0.6)千克]和双胞胎女孩[2.4(0.5)千克]的出生体重在不同的受孕类型之间没有差异。在3个月大的单胎婴儿队列中,ICSI的血清IGF-I低于NC男孩[94(27)ng / ml,P <0.001]和IVF [74( 34)ng / ml],而NC女生则为[93(43)ng / ml,P = 0.011]。与3岁儿童相比,ICSI儿童在3岁时也小于其目标身高(sd评分)[平均-0.91(1.2)],而NC儿童则为[-0.61(0.9),P = 0.033]。在儿童队列中,三组之间的目标身高获得(sd得分)和生长因子没有差异。
    结论:两组人群ICSI和IVF儿童的总体生长方式均正常。我们在辅助生殖技术和对照后出生的婴儿之间的目标身高获得和血清IGF-I水平细微差异的发现可能在临床上并不重要。但是,这些观察结果表明,需要对这些儿童的生长和青春期进行进一步的系统随访。
  • 【WT1 Wilms的肿瘤抑制基因是PC12细胞中胰岛素样生长因子I(IGF-1)作用的下游靶标。】 复制标题 收藏 收藏
    DOI:10.1111/j.1471-4159.2006.04119.x 复制DOI
    作者列表:Sarfstein R,Werner H
    BACKGROUND & AIMS: :The biological actions of the insulin-like growth factors, IGF-I and IGF-II, are mediated by the ligand-induced activation of the IGF-I receptor (IGF-IR), a transmembrane heterotetramer linked to the ras-raf-mitogen-activated protein kinase (MAPK) and phosphatidyl inositol 3 kinase (PI3K)-protein kinase B (PKB)/Akt signal transduction cascades. The Wilms' tumor suppressor gene (wt1) encodes a zinc finger transcription factor, WT1, which has been implicated in various cellular processes including proliferation, differentiation and apoptosis. In the present study we demonstrated that IGF-I modulates the WT1 gene expression in neurally derived PC12 cells in a dose- and time-dependent manner. This effect was mediated through both the MAPK and PI3-kinase signaling pathways, as shown by the ability of the specific inhibitors UO126 and LY294002 to abrogate IGF-I action. Moreover, using RT-PCR and transient transfection assays, we demonstrated that the IGF-I effect was associated with corresponding changes in WT1 mRNA levels and WT1 promoter activity. In addition, the results of the present study revealed that high WT1 levels were associated with the induction of apoptosis, whereas low WT1 levels were correlated with the inhibition of apoptosis, as demonstrated by poly ADP ribose polymerase (PARP) cleavage, Bax expression, Annexin V-FITC staining, and by the use of antisense oligonucleotides against WT1. In summary, our results show that the wt1 gene is a novel target for IGF-I action in neurally derived cells.
    背景与目标: 胰岛素样生长因子IGF-I和IGF-II的生物学作用是由配体诱导的IGF-I受体(IGF-IR)活化而介导的,IGF-IR受体是与ras-raf-连接的跨膜异四聚体丝裂原活化蛋白激酶(MAPK)和磷脂酰肌醇3激酶(PI3K)-蛋白激酶B(PKB)/ Akt信号转导级联反应。威尔姆斯的肿瘤抑制基因(wt1)编码锌指转录因子WT1,该因子已参与多种细胞过程,包括增殖,分化和凋亡。在本研究中,我们证明了IGF-1以剂量和时间依赖性的方式调节神经源性PC12细胞中WT1基因的表达。这种作用是通过MAPK和PI3激酶信号传导途径介导的,如特异性抑制剂UO126和LY294002消除IGF-I作用的能力所示。此外,使用RT-PCR和瞬时转染试验,我们证明了IGF-I的作用与WT1 mRNA水平和WT1启动子活性的相应变化有关。此外,本研究结果表明,高WT1水平与凋亡诱导相关,而低WT1水平与凋亡抑制相关,如聚ADP核糖聚合酶(PARP)裂解,Bax表达,膜联蛋白所证明的。 V-FITC染色,并使用针对WT1的反义寡核苷酸。总而言之,我们的结果表明wt1基因是神经衍生细胞中IGF-I作用的新靶标。
  • 【比目鱼肌的代谢特征与高血压父母的后代中胰岛素作用有关。】 复制标题 收藏 收藏
    DOI:10.1016/j.metabol.2006.06.010 复制DOI
    作者列表:Kratochvílová S,Vyhnanovská P,Vlasáková Z,Hájek M,Skibová J,Pelikánová T
    BACKGROUND & AIMS: :Insulin resistance affecting skeletal muscle metabolism is present in the prehypertensive state. The aim of our study was to test the hypothesis that blood pressure value is related to skeletal muscle composition, measured by (31)P magnetic resonance (MR) spectroscopy, and to insulin sensitivity in the offspring of hypertensive parents (OH) and healthy controls. Study groups consisted of 10 healthy young lean OH with normal glucose tolerance, confirmed with oral glucose tolerance test, and 13 controls matched for age, sex, and body mass index. Insulin action was estimated as glucose disposal (M), glucose metabolic clearance rate (MCR), and insulin sensitivity index (M/I) during a 10-hour hyperinsulinemic euglycemic clamp. The sum of immunoreactive insulin values from the oral glucose tolerance test was calculated. (31)P MR spectroscopy was performed on a whole-body MR scanner (Siemens Vision, Erlangen, Germany) operating at 1.5 T and equipped with actively shielded gradient coils. There were no differences in common metabolic and anthropometric parameters between OH and controls except for the blood pressure, which was in the range of normal to high-normal level in OH. Mean blood pressure was significantly higher in OH (95.73 +/- 4.39 vs 83.76 +/- 3.95 mm Hg; P < .001). Trend toward insulin resistance was registered in OH with significantly lower M/I (0.74 +/- 0.47 vs 1.42 +/- 0.65 mg x kg(-1) x min(-1) x mIU(-1) x L(-1); P < .05). There were no significant differences in total serum magnesium (sMg) levels between OH and controls, although a positive correlation exists between sMg and insulin sensitivity expressed as M (r = 0.63, P < .01), MCR (r = 0.54, P < .01), and M/I (r = 0.51, P < .05). No differences in signal intensities of phosphocreatine (PCr), phosphomonoesters, phosphodiesters, inorganic phosphates (Pi), adenosine triphosphates (Patp and betaATP), and calculated concentrations of intracellular ionized magnesium (Mgi) and H(+) ions between the groups were detected. Systolic blood pressure correlates positively with PCr/Patp (r = 0.43, P < .05), Pi/Patp (r = 0.413, P < .05), and Pi/betaATP (r = 0.48, P < .05). Diastolic blood pressure correlates positively only with the ratio Pi/betaATP (r = 0.42, P < .05). The sum of immunoreactive insulin values correlates with PCr/betaATP (r = 0.53, P < .01) and with Pi/betaATP (r = 0.6, P < .01). In conclusion, increase in blood pressure and insulin resistance were confirmed in offspring of OH. Insulin sensitivity is related to sMg and the elevation of blood pressure is associated with the activation of energy metabolism in skeletal muscle. The relationship between muscle energetic characteristics and markers of insulin resistance suggests that the alteration of energy metabolism may be present in early stages of metabolic syndrome.
    背景与目标: :在高血压前状态下,会影响骨骼肌新陈代谢的胰岛素抵抗。我们研究的目的是检验以下假设:血压值与通过(31)P磁共振(MR)光谱法测量的骨骼肌成分以及高血压父母(OH)和健康对照的后代的胰岛素敏感性有关。研究组包括10名健康正常的年轻瘦肉OH,其葡萄糖耐量正常,经口服葡萄糖耐量试验确认,另有13个对照的年龄,性别和体重指数匹配。在10小时高胰岛素正常血糖钳制期间,胰岛素作用估计为葡萄糖处置(M),葡萄糖代谢清除率(MCR)和胰岛素敏感性指数(M / I)。计算来自口服葡萄糖耐量试验的免疫反应性胰岛素值的总和。 (31)P MR光谱是在全身MR扫描仪(Siemens Vision,Erlangen,德国)上以1.5 T操作并配备有源屏蔽梯度线圈进行的。 OH和对照组之间的共同代谢和人体测量学参数没有差异,除了血压处于OH正常水平到高正常水平的范围之内。 OH的平均血压显着升高(95.73 /-4.39与83.76 /-3.95 mm Hg; P <.001)。在OH中出现胰岛素抵抗的趋势,M / I显着降低(0.74 /-0.47对1.42 /-0.65 mg x kg(-1)x min(-1)x mIU(-1)x L(-1); P <.05)。尽管sMg与胰岛素敏感性之间呈正相关,以M(r = 0.63,P <.01),MCR(r = 0.54,P < .01)和M / I(r = 0.51,P <.05)。在两组之间没有发现磷酸肌酸(PCr),磷酸单酯,磷酸二酯,无机磷酸盐(Pi),三磷酸腺苷(Patp和betaATP)的信号强度以及计算出的细胞内离子化镁(Mgi)和H()浓度的差异。收缩压与PCr / Patp(r = 0.43,P <.05),Pi / Patp(r = 0.413,P <.05)和Pi / betaATP(r = 0.48,P <.05)正相关。舒张压仅与Pi / betaATP比率呈正相关(r = 0.42,P <.05)。免疫反应性胰岛素值的总和与PCr / betaATP(r = 0.53,P <.01)和Pi / betaATP(r = 0.6,P <.01)相关。总之,在OH的后代中证实了血压升高和胰岛素抵抗。胰岛素敏感性与sMg有关,血压升高与骨骼肌能量代谢的激活有关。肌肉能量特性与胰岛素抵抗标志物之间的关系表明,能量代谢的改变可能在代谢综合征的早期出现。
  • 【在一项1型糖尿病患者的随机试验中测试的分散注射策略的结果是,门冬胰岛素的吸收得到增强。】 复制标题 收藏 收藏
    DOI:10.2337/dc12-1319 复制DOI
    作者列表:Mader JK,Birngruber T,Korsatko S,Deller S,Köhler G,Boysen S,Augustin T,Mautner SI,Sinner F,Pieber TR,AP@home Consortium.
    BACKGROUND & AIMS: OBJECTIVE:We investigated the impact of two different injection strategies on the pharmacokinetics and pharmacodynamics of insulin aspart in vivo in an open-label, two-period crossover study and verified changes in the surface-to-volume ratio ex vivo. RESEARCH DESIGN AND METHODS:Before the clinical trial, insulin aspart was injected ex vivo into explanted human abdominal skin flaps. The surface-to-volume ratio of the subcutaneous insulin depot was assessed by microfocus computed tomography that compared 1 bolus of 18 IU with 9 dispersed boluses of 2 IU. These two injection strategies were then tested in vivo, in 12 C-peptide-negative type 1 diabetic patients in a euglycemic glucose clamp (glucose target 5.5 ± 1.1 mmol/L) for 8 h after the first insulin administration. RESULTS:The ex vivo experiment showed a 1.8-fold higher mean surface-to-volume ratio for the dispersed injection strategy. The maximum glucose infusion rates (GIR) were similar for the two strategies (10 ± 4 vs. 9 ± 4; P = 0.5); however, times to reach maximum GIR and 50% and 10% of the maximum GIR were significantly reduced by using the 9 × 2 IU strategy (68 ± 33 vs. 127 ± 93 min; P = 0.01; 38 ± 9 vs. 49 ± 16 min; P < 0.01; 23 ± 6 vs. 30 ± 10 min; P < 0.05). For 9 × 2 IU, the area under the GIR curve was greater during the first 60 min (219 ± 89 vs. 137 ± 75; P < 0.01) and halved until maximum GIR (242 ± 183 vs. 501 ± 396; P < 0.01); however, it was similar across the whole study period (1,361 ± 469 vs. 1,565 ± 527; P = 0.08). CONCLUSIONS:A dispersed insulin injection strategy enhanced the effect of a fast-acting insulin analog. The increased surface-to-volume ratio of the subcutaneous insulin depot can facilitate insulin absorption into the vascular system.
    背景与目标: 目的:我们在开放标签,两期交叉研究中研究了两种不同的注射策略对体内门冬胰岛素的药代动力学和药效学的影响,并验证了离体表面积与体积比的变化。
    研究设计和方法:在临床试验之前,将门冬胰岛素离体注射到植入的人腹部皮肤皮瓣中。皮下胰岛素贮存库的表面体积比是通过微焦点计算机断层扫描评估的,该技术比较了1推注的18 IU和9分散推注的2 IU。然后,在首次胰岛素注射后的正常血糖葡萄糖钳位(葡萄糖靶标5.5±1.1 mmol / L)中的12名C肽阴性1型糖尿病患者体内测试了这两种注射策略。
    结果:离体实验显示,分散注射策略的平均表面体积比高1.8倍。两种策略的最大葡萄糖输注速率(GIR)相似(10±4 vs. 9±4; P = 0.5);但是,通过使用9×2 IU策略,达到最大GIR以及达到最大GIR的时间分别减少了50%和10%(68±33 vs. 127±93 min; P = 0.01; 38±9 vs. 49± 16分钟; P <0.01; 23±6 vs. 30±10分钟; P <0.05)。对于9×2 IU,在最初的60分钟内GIR曲线下的面积更大(219±89对137±75; P <0.01),并且减半直到最大GIR(242±183对501±396对; P < 0.01);但是,在整个研究期间,情况相似(1361±469对1,565±527; P = 0.08)。
    结论:分散胰岛素注射策略增强了速效胰岛素类似物的作用。皮下胰岛素贮存库增加的表面积与体积之比可以促进胰岛素吸收进入血管系统。
  • 【肥胖男性中大剂量白藜芦醇的补充:一项由研究人员发起,随机,安慰剂对照的底物代谢,胰岛素敏感性和身体成分的临床试验。】 复制标题 收藏 收藏
    DOI:10.2337/db12-0975 复制DOI
    作者列表:Poulsen MM,Vestergaard PF,Clasen BF,Radko Y,Christensen LP,Stødkilde-Jørgensen H,Møller N,Jessen N,Pedersen SB,Jørgensen JO
    BACKGROUND & AIMS: :Obesity, diabetes, hypertension, and hyperlipidemia constitute risk factors for morbidity and premature mortality. Based on animal and in vitro studies, resveratrol reverts these risk factors via stimulation of silent mating type information regulation 2 homolog 1 (SIRT1), but data in human subjects are scarce. The objective of this study was to examine the metabolic effects of high-dose resveratrol in obese human subjects. In a randomized, placebo-controlled, double-blinded, and parallel-group design, 24 obese but otherwise healthy men were randomly assigned to 4 weeks of resveratrol or placebo treatment. Extensive metabolic examinations including assessment of glucose turnover and insulin sensitivity (hyperinsulinemic euglycemic clamp) were performed before and after the treatment. Insulin sensitivity, the primary outcome measure, deteriorated insignificantly in both groups. Endogenous glucose production and the turnover and oxidation rates of glucose remained unchanged. Resveratrol supplementation also had no effect on blood pressure; resting energy expenditure; oxidation rates of lipid; ectopic or visceral fat content; or inflammatory and metabolic biomarkers. The lack of effect disagrees with persuasive data obtained from rodent models and raises doubt about the justification of resveratrol as a human nutritional supplement in metabolic disorders.
    背景与目标: 肥胖,糖尿病,高血压和高脂血症是发病率和过早死亡的危险因素。根据动物和体外研究,白藜芦醇通过刺激无声交配类型信息调节2同源物1(SIRT1)来逆转这些危险因素,但人类受试者的数据却很少。这项研究的目的是检查高剂量白藜芦醇在肥胖人类受试者中的代谢作用。在随机,安慰剂对照,双盲和平行组设计中,将24名肥胖但其他方面健康的男性随机分配到白藜芦醇或安慰剂治疗4周。在治疗之前和之后进行了广泛的代谢检查,包括评估葡萄糖更新和胰岛素敏感性(高胰岛素正常血糖钳夹)。两组的主要结果指标胰岛素敏感性均无显着性恶化。内源性葡萄糖的产生以及葡萄糖的周转率和氧化率保持不变。补充白藜芦醇对血压也没有影响。静态能量消耗;脂质的氧化速率;异位或内脏脂肪含量;或炎症和代谢生物标志物。缺乏效果与从啮齿动物模型获得的有说服力的数据不同,并引起人们对白藜芦醇作为代谢障碍中人类营养补充剂的合理性的怀疑。
  • 【高胰岛素血症,胰岛素抵抗和高血压大鼠的米贝非对慢性T型Ca2通道的阻滞作用。】 复制标题 收藏 收藏
    DOI:10.1016/s0008-6363(97)00032-1 复制DOI
    作者列表:Verma S,Bhanot S,Hicke A,McNeill JH
    BACKGROUND & AIMS: OBJECTIVES:To determine the effects of calcium antagonists on hyperinsulinemia, hypertriglyceridemia and hypertension, we examined the long-term effects of a new calcium channel blocker, mibefradil, on plasma insulin levels, plasma triglyceride levels and systolic blood pressure in insulin-resistant and hyperinsulinemic fructose-hypertensive (FH) rats. To this aim, both prevention and reversal protocols were employed.

    METHODS:Prevention study: Male Sprague-Dawley rats were procured at 6 weeks of age and were divided into: control (C, n = 6), control-treated (CT, n = 5), fructose (F, n = 7) and fructose-treated (FT, n = 6). Baseline measurements of plasma glucose, insulin and systolic blood pressure were conducted in all groups. At week 7, chronic mibefradil treatment (30 mg/kg/day, orally for 6 weeks) was initiated in the CT and FT groups. At week 8, the rats in the F and FT groups were started on a 66% fructose diet to induce hyperinsulinemia and hypertension. Weekly measurements of plasma insulin, plasma triglycerides and systolic blood pressure were conducted for the following 4 weeks. Reversal protocol: In a separate study, 8-week-treated FH rats and their age-matched controls were used to examine the effects of mibefradil on reversing fructose-induced hyperinsulinemia and hypertension.

    RESULTS:The F group exhibited hyperinsulinemia (3.2 +/- 0.1 vs. C 2.3 +/- 0.07 ng/ml, P < 0.05), hypertension (148 +/- 3 vs. C 121 +/- 1 mmHg, P < 0.002) and elevated triglyceride levels (5.4 +/- 0.8 vs. C 1.6 +/- 0.3 mM, P < 0.05). Chronic mibefradil treatment prevented the development of hyperinsulinemia (1.6 +/- 0.08 ng/ml, P < 0.004 vs. F) and hypertension (123 +/- 1 mmHg. P < 0.001 vs. F) and attenuated the development of hypertriglyceridemia. In the reversal study, mibefradil treatment reversed the development of hyperinsulinemia, hypertriglyceridemia and elevated BP in FH rats. Treatment did not affect the plasma glucose levels in any group (prevention or reversal).

    CONCLUSIONS:Long-term treatment with the calcium antagonist, mibefradil, both prevents and reverses the development of hyperinsulinemia, hypertriglyceridemia and hypertension in FH rats. These data indicate beneficial effects of mibefradil on carbohydrate and lipid metabolism in hyperinsulinemic and insulin-resistant states.

    背景与目标: 目标:为了确定钙拮抗剂对高胰岛素血症,高甘油三酯血症和高血压的影响,我们研究了新型钙通道阻滞剂米贝拉地对血浆胰岛素水平,血浆甘油三酸酯水平和收缩期血液的长期影响胰岛素抵抗和高胰岛素果糖高血压(FH)大鼠的血压升高。为此目的,采用了预防和逆转方案。

    方法:预防研究:雄性Sprague-Dawley大鼠在6周龄时采购,分为:对照组(C组) ,n = 6),对照处理(CT,n = 5),果糖(F,n = 7)和果糖处理(FT,n = 6)。在所有组中进行血浆葡萄糖,胰岛素和收缩压的基线测量。在第7周时,在CT和FT组中开始了慢性米贝地尔治疗(30 mg / kg /天,口服6周)。在第8周,F和FT组的大鼠开始以66%的果糖饮食开始,以诱导高胰岛素血症和高血压。在接下来的4周中每周进行一次血浆胰岛素,血浆甘油三酸酯和收缩压的测量。逆转方案:在一项单独的研究中,使用经过8周治疗的FH大鼠及其年龄匹配的对照,检查了米贝拉地尔对逆转果糖诱导的高胰岛素血症和高血压的作用。

    结果:F组表现出高胰岛素血症(3.2 /-0.1 vs. C 2.3 /-0.07 ng / ml,P <0.05),高血压(148 /-3 vs. C 121 /-1 mmHg,P <0.002)并升高甘油三酸酯水平(5.4 /-0.8 vs. C 1.6 /-0.3 mM,P <0.05)。慢性米贝拉地尔治疗可预防高胰岛素血症(1.6 /-0.08 ng / ml,P <0.004 vs. F)和高血压(123 /-1 mmHg。P <0.001 vs. F)的发生,并减轻高甘油三酯血症的发生。在逆转研究中,米贝拉地尔治疗逆转了FH大鼠高胰岛素血症,高甘油三酸酯血症和BP升高的发展。治疗并未影响任何组的血浆葡萄糖水平(预防或逆转)。

    结论:长期用钙拮抗剂米贝拉地尔治疗既能预防又能逆转糖尿病的发展。 FH大鼠的高胰岛素血症,高甘油三酸酯血症和高血压。这些数据表明米贝拉地尔在高胰岛素血症和胰岛素抵抗状态下对碳水化合物和脂质代谢的有益作用。

  • 【胰岛素的半合成类似物。甲硫氨酸的N-取代衍生物作为酸稳定的保护基的用途。】 复制标题 收藏 收藏
    DOI:10.1042/bj1650479 复制DOI
    作者列表:Saunders DJ,Offord R
    BACKGROUND & AIMS: 1. We describe the use of benzyloxycarbonylmethionine and ethoxycarbonylmethionine for the selective protection of the amino groups of glycine-A1 and lysine-B29 of pig insulin. We have used the Edman method to remove residues from the N-terminal and of the B-chain of the N(A1)N(B29)-di-protected derivatives. The benzyloxycarbonyl group shows slight but noticeable lability in the acid-cleavage step, but the ethoxycarbonyl group remained intact even after five cycles of degradation. 2. We have prepared the following truncated forms of insulin via the di(ethoxycarbonylmethionyl) derivativedes-Phe(B1)-insulin;des-(Phe(B1)-Val(B2))-insulin; des-(Phe(B1)-Val(B2)-Asn(B3))-insulin;des- (Phe(B1)-Val(B2)-Asn(B3)-Gln(B4))-insulin; des-(Phe(B1)-Val(B2)-Asn(B3) -Gln(B4)-His(B5))-insulin. 3. Insulin was re-synthesized from the di-protected des-Phe(B1)-insulin by reaction with an active ester of t-butoxycarbonyl-l-phenylalanine. The product after deprotection crystallized, and the immunoreactivity of the crystalline material was identical with that of the native protein. 4.

    We have prepared the following analogues of insulin in a similar manner[l-Ala(B1)]insulin; [l-Val(B1)]insulin; [l-Tyr(B1)]insulin; [m-F-l-Phe(B1)]insulin; [o-F-l-Phe(B1)]-insulin; [o-F-l-Phe(B2)]des-Phe(B1)-insulin. All had between 34 and 62% of the activity of insulin in the fat-cell test. 5. We have also investigated the use of the benzyol, toluene-p-sulphonyl, p-nitrobenzyloxycarbonyl and 2,4-dinitrophenyl groups for the N-protection of the methionine active esters. Each should have had some particular advantage over the benzyloxycarbonyl and ethoxycarbonyl groups, but all proved in practice to have disadvantages that more than outweighed anything in their favour.

    背景与目标: 1.我们描述了使用苄氧羰基蛋氨酸和乙氧羰基蛋氨酸选择性保护猪胰岛素的甘氨酸-A1和赖氨酸-B29的氨基。我们已经使用Edman方法从N(A1)N(B29)-di-protected衍生物的N末端和B链中去除残基。苄氧基羰基在酸裂解步骤中显示出轻微但明显的不稳定性,但是即使经过五个降解循环,乙氧基羰基仍保持完整。 2.我们通过二(乙氧基羰基甲硫酰基)衍生物des-Phe(B1)-胰岛素; des-(Phe(B1)-Val(B2))-胰岛素制备了以下截短形式的胰岛素; des-(Phe(B1)-Val(B2)-Asn(B3))-胰岛素; des-(Phe(B1)-Val(B2)-Asn(B3)-Gln(B4))-胰岛素; des-(Phe(B1)-Val(B2)-Asn(B3)-Gln(B4)-His(B5))-胰岛素。 3.通过与叔丁氧羰基-1-苯基丙氨酸的活性酯反应,从双保护的des-Phe(B1)-胰岛素重新合成胰岛素。脱保护后的产物结晶,并且该结晶物质的免疫反应性与天然蛋白质的免疫反应性相同。 4.
    我们以相似的方式制备了以下胰岛素类似物[1-Ala(B1)]胰岛素; [l-Val(B1)]胰岛素; [1-Tyr(B1)]胰岛素; [m-F-1-Phe(B1)]胰岛素; [o-F-1-Phe(B1)]-胰岛素; [o-F-1-Phe(B2)] des-Phe(B1)-胰岛素。在脂肪细胞试验中,所有人的胰岛素活性在34%至62%之间。 5.我们还研究了苯甲酚,甲苯-对-磺酰基,对-硝基苄氧基羰基和2,4-二硝基苯基用于甲硫氨酸活性酯的N-保护。每种化合物都应比苄氧羰基和乙氧羰基有一些特殊的优点,但是在实践中所有这些都被证明具有弊端,胜过任何对它们有利的事情。

  • 【胰岛素样生长因子I在人跟腱中的表达,含量和定位。】 复制标题 收藏 收藏
    DOI:10.1080/03008200600809893 复制DOI
    作者列表:Olesen JL,Heinemeier KM,Langberg H,Magnusson SP,Kjaer M,Flyvbjerg A
    BACKGROUND & AIMS: :In animals insulin-like growth factor I (IGF-I) stimulates collagen production by fibroblasts and is expressed in tendons together with its binding protein 4 (IGFBP-4). However, the presence of IGF-I and IGFBP-4 in human tendon tissue is not described. Tissue IGF-I content was examined by immunoflourometric assay, real-time PCR, and immunohistochemistry used to localize and determine expression of IGF-I and IGFBP-4 in 6 postmortem human Achilles tendons. Tendon tissue concentrations of IGF-I were found to be 0.53 +/- 0.10 ng/g. Furthermore, we demonstrated that IGF-I and IGFBP-4 are localized around the tendon fibroblasts and that mRNA for IGF-I and IGFBP-4 can be determined in human tendon tissue. The present study adds support for the roles of IGF-I and IGFBP-4 in the regulation of tendon adaptive responses to mechanical loading.
    背景与目标: :在动物中,胰岛素样生长因子I(IGF-I)刺激成纤维细胞产生胶原蛋白,并在肌腱及其结合蛋白4(IGFBP-4)中表达。然而,没有描述人肌腱组织中IGF-1和IGFBP-4的存在。通过免疫荧光测定,实时PCR和免疫组化法检测组织IGF-I的含量,以定位和确定6个死后人类跟腱中IGF-I和IGFBP-4的表达。发现IGF-1的肌腱组织浓度为0.53±0.10ng / g。此外,我们证明了IGF-1和IGFBP-4位于肌腱成纤维细胞周围,并且可以在人的肌腱组织中确定IGF-1和IGFBP-4的mRNA。本研究增加了对IGF-I和IGFBP-4在调节肌腱对机械负荷的适应性反应中的作用的支持。
  • 【生长激素和胰岛素样生长因子结合蛋白的作用。】 复制标题 收藏 收藏
    DOI:10.1159/000181492 复制DOI
    作者列表:Hintz RL
    BACKGROUND & AIMS: :Some peptide hormones are associated with specific, high-affinity plasma proteins. The major binding protein (BP) for growth hormone (GH) in humans is a circulating fragment of the GH membrane receptor, consisting of the hydrophilic, extracellular portion of that transmembrane glycoprotein. The circulating levels of GH-BP mirror the levels of GH receptors. There are 4 well-characterized insulin-like growth factor (IGF)-BPs. One IGF-binding component in plasma is a fragment of the extracellular portion of the IGF-II/mannose-6-phosphate receptor, analogous to the GH-BP. The 3 other cloned IGF-BPs form a homologous family of proteins with differences in structure, glycosylation and hormonal control that suggest differences in function. The GH- and IGF-BPs play a major role in the metabolism and biological action of these peptide hormones.
    背景与目标: :某些肽激素与特定的高亲和力血浆蛋白有关。人类生长激素(GH)的主要结合蛋白(BP)是GH膜受体的循环片段,由该跨膜糖蛋白的亲水性细胞外部分组成。 GH-BP的循环水平反映了GH受体的水平。有4个特征明确的胰岛素样生长因子(IGF)-BP。血浆中的一种IGF结合成分是IGF-II /甘露糖6-磷酸受体的胞外部分的片段,类似于GH-BP。其他3个克隆的IGF-BPs形成同源的蛋白质家族,其结构,糖基化和激素控制方面存在差异,提示其功能存在差异。 GH-和IGF-BP在这些肽激素的代谢和生物学作用中起主要作用。
  • 【白藜芦醇通过阻断β细胞的K(ATP)和K(V)通道增强胰岛素分泌。】 复制标题 收藏 收藏
    DOI:10.1016/j.ejphar.2007.04.062 复制DOI
    作者列表:Chen WP,Chi TC,Chuang LM,Su MJ
    BACKGROUND & AIMS: :The present study investigated the effect of resveratrol on the electrophysiology and insulin secretion of pancreatic beta cells, and examined resveratrol-induced alterations in insulin levels and plasma glucose of normal and streptozotocin-induced diabetic rats. Whole-cell voltage clamp study in the MIN6 cell, a mouse beta cell line, revealed that resveratrol significantly inhibited ATP-sensitive K(+) current at 3 micromol/l, and voltage-gated K(+) currents at 30 micromol/l. Ca(2+)-activated K(+) current was activated by resveratrol at 100 micromol/l. In MIN6 cells stained with membrane potential dye DiBAC(4)(5), resveratrol markedly depolarized membrane potential at the concentrations of 3-100 micromol/l. Insulin secretion was increased in the presence of resveratrol in MIN6, Hit-T15, and RIN-m5F cells. Resveratrol (3 mg/kg, i.p.) increased insulin secretion associated with a lowering in plasma glucose in normal rats, but not in streptozotocin-diabetic rats within the initial 60 min. In conclusion, resveratrol can act as an insulin-secretagogue through I(KATP) and I(KV) inhibition which can contribute to plasma glucose lowering effect in normal rats.
    背景与目标: :本研究调查了白藜芦醇对胰腺β细胞电生理和胰岛素分泌的影响,并研究了白藜芦醇诱导的正常和链脲佐菌素诱导的糖尿病大鼠胰岛素水平和血浆葡萄糖的变化。在MIN6细胞(一种小鼠​​β细胞系)中进行全细胞电压钳研究,发现白藜芦醇在3微摩尔/升时显着抑制ATP敏感的K()电流,在30微摩尔/升时抑制电压门控的K()电流。 Ca(2)激活的K()电流被白藜芦醇以100 micromol / l激活。在用膜电位染料DiBAC(4)(5)染色的MIN6细胞中,白藜芦醇在3-100 micromol / l的浓度下可显着去极化膜电位。在MIN6,Hit-T15和RIN-m5F细胞中存在白藜芦醇时,胰岛素分泌增加。在正常大鼠中,白藜芦醇(3 mg / kg,i.p.)在最初60分钟内胰岛素分泌增加与血浆葡萄糖降低有关,但在链脲佐菌素-糖尿病大鼠中却没有。总之,白藜芦醇可以通过I(KATP)和I(KV)抑制作用起胰岛素分泌的作用,这可以促进正常大鼠血浆葡萄糖的降低作用。
  • 【脂肪酸氧化途径作为胰岛素抵抗的治疗靶标。】 复制标题 收藏 收藏
    DOI:10.1517/14728222.10.5.749 复制DOI
    作者列表:Clapham JC,Storlien LH
    BACKGROUND & AIMS: :It is recognised that obesity is a major driver for insulin resistance and Type 2 diabetes in both adult and young members of diverse societies. Weight loss strategies involving diet, exercise and behaviour modification work only for the minority of highly motivated individuals, but fail completely in the vast majority; yet weight loss is associated with benefits in metabolic health. Why is it so difficult to maintain weight loss in the longer term? Here, the authors explore the possibility that energy partitioning, especially of lipids, plays a key role in both weight recidivism and, by association, insulin resistance. Drug targets that address key pathways important in this process, where progress in drug discovery is apparent, are discussed.
    背景与目标: :众所周知,肥胖是各种社会的成年和年轻成员中胰岛素抵抗和2型糖尿病的主要驱动力。涉及饮食,运动和行为改变的减肥策略仅对少数积极进取的人有效,但在绝大多数人中完全无效;减肥与代谢健康有关。为什么长期保持减肥如此困难?在这里,作者探索了能量分配(尤其是脂质)在体重减轻和胰岛素抵抗中起关键作用的可能性。讨论了解决在此过程中很重要的关键途径的药物靶标,在该过程中,药物发现有了明显的进展。
  • 【正常显性和同类卵泡,多囊性和多囊性卵巢的卵泡液中的胰岛素样生长因子结合蛋白。】 复制标题 收藏 收藏
    DOI:10.1111/j.1365-2265.1990.tb00465.x 复制DOI
    作者列表:Holly JM,Eden JA,Alaghband-Zadeh J,Carter GD,Jemmott RC,Cianfarani S,Chard T,Wass JA
    BACKGROUND & AIMS: :There is now considerable evidence that the insulin-like growth factors (IGFs) play an important role in the human ovary. It has also recently become apparent that the physiological activity of the IGFs is modulated by a number of specific binding proteins (IGFBPs). In order to understand the role of the IGFs in ovarian physiology, the presence and functions of these IGFBPs will need to be characterized. As an initial step towards this we have investigated the presence of the various binding proteins by Western ligand blotting and have measured the levels of one of them, IGFBP-1, in follicular fluid (FF) obtained from unstimulated dominant and cohort follicles in 19 normal women and in eight patients with polycystic and one with multicystic ovaries. In normal women, IGFBP-1 levels in dominant follicles were similar to matched serum levels but were significantly lower in cohort follicles. IGFBP-1 levels correlated with FF-volume (r = 0.58, P less than 0.001) and with paired serum levels (r = 0.63, P less than 0.001). In post-LH surge dominant follicles this relationship with serum levels no longer held and in three out of nine subjects FF levels were higher than in serum. Thus IGFBP-1 in normal human FF appears to be partly derived from the circulation but with additional local production in the larger developing dominant follicles. Western ligand blotting revealed five IGF-binding proteins in FF running parallel with those identified in serum, suggesting that the IGFBP species previously identified in serum may also be present in FF. The two bands in positions corresponding to the components of the large (150kDa) binding complex were, as in serum, the predominant forms and in most FF samples these were even more prominent than in the accompanying serum sample. This contrasts with previous studies in lymph which suggested that the 150kDa complex was largely retained in the circulation. All three small IGFBPs varied considerably between FF samples even within an individual; each IGFBP varied independently of the other IGFBPs. Our results demonstrate that at least four discrete IGFBPs are present in FF and suggest that each may be produced independently within the ovary.
    背景与目标: :现在有大量证据表明胰岛素样生长因子(IGF)在人卵巢中起重要作用。最近也已经很明显,IGF的生理活性受到许多特异性结合蛋白(IGFBP)的调节。为了理解IGF在卵巢生理中的作用,将需要表征这些IGFBP的存在和功能。作为对此的第一步,我们已通过Western配体印迹研究了各种结合蛋白的存在,并测量了19种正常人从未刺激的优势和同类卵泡中获得的卵泡液(FF)中其中一种IGFBP-1的水平。女性和8例多囊性卵巢癌患者和1例多囊性卵巢癌患者。在正常女性中,优势卵泡中的IGFBP-1水平与匹配的血清水平相似,但在同龄卵泡中则显着降低。 IGFBP-1水平与FF量(r = 0.58,P小于0.001)和成对的血清水平(r = 0.63,P小于0.001)相关。在LH激增后的主要卵泡中,这种与血清水平的关系不再成立,在9名受试者中,有3名的FF水平高于血清。因此,正常人FF中的IGFBP-1似乎部分来自循环,但在较大的发育中的优势卵泡中有额外的局部产生。 Western配体印迹显示FF中有5种IGF结合蛋白与血清中鉴定的蛋白平行运行,这表明先前在血清中鉴定出的IGFBP种类也可能存在于FF中。如在血清中,对应于大(150kDa)结合复合物组分的位置上的两个条带是主要形式,在大多数FF样品中,它们甚至比随附的血清样品中更为突出。这与先前的淋巴研究相反,后者表明150kDa的复合物主要保留在循环系统中。 FF样本之间的所有三个小型IGFBP甚至在一个个体中都存在很大差异。每个IGFBP均独立于其他IGFBP而变化。我们的结果表明,FF中至少存在4个离散的IGFBP,提示每个子可能在卵巢内独立产生。
  • 【血清视黄醇结合蛋白:肥胖,胰岛素抵抗和2型糖尿病之间的联系。】 复制标题 收藏 收藏
    DOI:10.1111/j.1753-4887.2007.tb00302.x 复制DOI
    作者列表:Wolf G
    BACKGROUND & AIMS: :Insulin resistance occurs under conditions of obesity, metabolic syndrome, and type 2 diabetes. It was found to be accompanied by down-regulation of the insulin-responsive glucose transporter GLUT4. Decreased adipocyte GLUT4 caused secretion by adipocytes of the serum retinol-binding protein RBP4. Enhanced levels of serum RBP4 appeared to be the signal for the development of systemic insulin resistance both in experimental animals and in humans. In mice, increased levels of serum RBP4 led to impaired glucose uptake into skeletal muscle and increased glucose production by liver, whereas lowered serum RBP4 levels greatly enhanced insulin sensitivity. Thus, a link has been established between obesity and insulin resistance: RBP4, the vitamin A-transport protein secreted into the circulation by adipocytes.
    背景与目标: 胰岛素抵抗在肥胖,代谢综合症和2型糖尿病的情况下发生。发现伴随着胰岛素反应性葡萄糖转运蛋白GLUT4的下调。脂肪细胞GLUT4减少导致脂肪细胞分泌视黄醇结合蛋白RBP4。血清RBP4水平升高似乎是实验动物和人类体内系统性胰岛素抵抗发展的信号。在小鼠中,血清RBP4水平升高会导致葡萄糖吸收到骨骼肌中,并增加肝脏产生的葡萄糖,而降低血清RBP4水平会大大增强胰岛素敏感性。因此,在肥胖与胰岛素抵抗之间建立了联系:RBP4,脂肪细胞分泌到循环中的维生素A转运蛋白。

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