共查询到20条相似文献，搜索用时 500 毫秒
1.
The addition of glucose stimulated release of insulin from the isolated islet tissue of the toadfish incubated in vitro. Reduced nicotinamide-adenine dinucleotide also stimulated insulin release, whereas the oxidized form had no effect. Both oxidized and reduced nicotinamide-adenine dinucleatide phosphate stimulated insulin release, but the reduced form was significantly more effective. 相似文献
2.
Adenosine 3',5'-monophosphate in pancreatic islets: glucose-induced insulin release 总被引：13，自引：0，他引：13
M A Charles R Fanska F G Schmid P H Forsham G M Grodsky 《Science (New York, N.Y.)》1973,179(73):569-571
Glucose-induced release of insulin from perifused rat islets is associated with elevated islet adenosine 3',5'-monophosphate. If values for adenosine 3',5'-monophosphate are compared to insulin release during theophylline or glucose stimulation and theophylline plus glucose stimulation, it suggests a minor role for adenosine 3',5'-monophosphate in directly stimulating insulin release but a prominent role in modulating glucose-induced release of insulin. 相似文献
3.
Underexpression of beta cell high Km glucose transporters in noninsulin-dependent diabetes 总被引：15，自引：0，他引：15
J H Johnson A Ogawa L Chen L Orci C B Newgard T Alam R H Unger 《Science (New York, N.Y.)》1990,250(4980):546-549
The role of defective glucose transport in the pathogenesis of noninsulin-dependent diabetes (NIDDM) was examined in Zucker diabetic fatty rats, a model of NIDDM. As in human NIDDM, insulin secretion was unresponsive to 20 mM glucose. Uptake of 3-O-methylglucose by islet cells was less than 19% of controls. The beta cell glucose transporter (GLUT-2) immunoreactivity and amount of GLUT-2 messenger RNA were profoundly reduced. Whenever fewer than 60% of beta cells were GLUT-2-positive, the response to glucose was absent and hyperglycemia exceeded 11 mM plasma glucose. We conclude that in NIDDM underexpression of GLUT-2 messenger RNA lowers high Km glucose transport in beta cells, and thereby impairs glucose-stimulated insulin secretion and prevents correction of hyperglycemia. 相似文献
4.
Zwillich T 《Science (New York, N.Y.)》2000,289(5479):531-533
When researchers in Edmonton, Canada, announced last month that a new procedure for transplanting pancreatic islet cells had freed seven adults with type I diabetes from taking insulin, the results generated a great deal of public enthusiasm. Some important caveats tended to get lost, however. One drawback is that transplant recipients would need to take immunosuppressive drugs for the rest of their lives to keep from rejecting the tissue. But more importantly, even if the benefits of the transplants outweigh the risks of the drugs, there's just not enough islet tissue to go around and there won't be anytime soon. 相似文献
5.
6.
用含低微量元素、维生素的饲料(L)和含高适量微量元素和维生素的饲料(H)分别喂养小鼠4周,采用腹腔注射ALX建立DM小鼠模型。血糖仪检测血糖结果,并在光镜下观察两组鼠胰岛细胞的形态变化。结果表明L组喂养的小鼠血糖明显上升,胰岛内分泌细胞排列稀疏不均,胰岛数及岛内细胞数减少;H组小鼠血糖基本维持正常水平,胰岛为圆形、椭圆形细胞团,境界清楚,胰岛数及岛内细胞数较多,内各分泌细胞大小一致。总之,DM发生前,微量元素和维生素的联合生物学效应可拮抗ALX引起的胰岛损害,保护胰岛细胞,使血糖维持正常水平。 相似文献
7.
Insulin biosynthesis: evidence for a precursor 总被引：48，自引：0，他引：48
Human islet cell tumor tissue and isolated islets of Langerhans from rats incorporated radioactive amino acids in vitro into insulin and a larger acid-alcohol soluble protein which could be separated from insulin by gel filtration. The amino acids were incorporated into the larger protein earlier than into insulin; only after incubation of islets for approximately 30 minutes did radioactivity begin to appear in insulin. The transfer of about 70 percent of the radioactivity of the larger protein to insulin was demonstrated in the absence of new peptide bond synthesis (cycloheximide), or during incubation with unlabeled amino acid (chase). The results indicate that the larger protein is a precursor in the biosynthesis of insulin. The name "proinsulin" is suggested for this protein. 相似文献
8.
Fukuhara A Matsuda M Nishizawa M Segawa K Tanaka M Kishimoto K Matsuki Y Murakami M Ichisaka T Murakami H Watanabe E Takagi T Akiyoshi M Ohtsubo T Kihara S Yamashita S Makishima M Funahashi T Yamanaka S Hiramatsu R Matsuzawa Y Shimomura I 《Science (New York, N.Y.)》2005,307(5708):426-430
Fat tissue produces a variety of secreted proteins (adipocytokines) with important roles in metabolism. We isolated a newly identified adipocytokine, visfatin, that is highly enriched in the visceral fat of both humans and mice and whose expression level in plasma increases during the development of obesity. Visfatin corresponds to a protein identified previously as pre-B cell colony-enhancing factor (PBEF), a 52-kilodalton cytokine expressed in lymphocytes. Visfatin exerted insulin-mimetic effects in cultured cells and lowered plasma glucose levels in mice. Mice heterozygous for a targeted mutation in the visfatin gene had modestly higher levels of plasma glucose relative to wild-type littermates. Surprisingly, visfatin binds to and activates the insulin receptor. Further study of visfatin's physiological role may lead to new insights into glucose homeostasis and/or new therapies for metabolic disorders such as diabetes. 相似文献
9.
日粮不同能量水平对乌金猪脂肪组织Leptin和RBP4基因表达的影响 总被引：1，自引：0，他引：1
研究日粮不同能量水平对乌金猪脂肪组织中脂肪细胞分泌因子leptin和RBP4基因表达的影响。选取体重约15kg的乌金猪54头,随机分为3组,分别饲喂消化能为14.22,12.89,11.74MJ/kg的日粮,在30,60,100kg体重时屠宰,分别测定血液中胰岛素和葡萄糖含量及胴体脂肪沉积率,取皮下脂肪组织用荧光定量PCR检测leptin和RBP4基因的表达水平。结果显示,饲喂高能量日粮乌金猪胴体脂肪沉积率和血液胰岛素含量高于饲喂低能量日粮组（P<0.05）,日粮能量水平对血液葡萄糖含量无明显影响（P>0.05）;脂肪组织中leptin基因的表达水平升高（P<0.05）,RBP4基因的表达水平降低（P<0.05）。表明高能量日粮通过上调leptin基因的表达、下调RBP4基因的表达,和胰岛素的作用促进脂肪沉积。 相似文献
10.
在键脲佐菌素（Ｓｔｒｅｐｔｏｚｏｔｉｎ ＳＴＺ）诱导建立的大鼠糖尿病模型基础上,将仙人掌汁液用于治疗糖尿病鼠,结果显示：饮用仙人掌汁液的糖尿病鼠其葡萄糖耐量及血清胰岛素水平恢复正常;而不饮者水平仍异常。研究提示仙人掌汁液有治疗糖尿病,改善胰岛素抵抗的作用。 相似文献
11.
为了研究三氯化铬与大鼠胰岛细胞共培养对胰岛细胞活性与胰岛素分泌水平的影响,并对其影响机制进行探讨,以台盼蓝染色法和MTT法检测胰岛β细胞活性,以不同浓度葡萄糖刺激胰岛素释放评价三氯化铬对胰岛细胞功能的影响,同时以RT-PCR检测胰岛细胞的抗凋亡基因bcl-2的表达。结果发现,随培养液中三氯化铬浓度的增加,胰岛活性随之增加,凋亡率降低,但2.0μmol/L的活性有所降低,凋亡率与对照组没有显著差异(P>0.05)。低糖和高糖浓度环境中试验组与对照组的胰岛素分泌没有显著差异(P<0.05),RT-PCR发现试验组的bcl-2表达显著高于对照组(P<0.05)。2.0μmol/L CrCl3明显降低胰岛细胞的凋亡率,提高其存活率,改善胰岛功能。 相似文献
12.
目的观察口服和静脉注射重组hGLP-1类似物对糖尿病大鼠血糖、胰岛素及胰岛组织病变的影响。方法用链脲佐菌素（STZ）建立SD大鼠糖尿病模型,随机分为模型组、灌胃组和注射组,每组10只,分别给予生理盐水灌胃、重组hGLP-1类似物多肽灌胃、hGLP-1类似物基因重组载体尾静脉注射,观察4周内各组大鼠血糖、胰岛素、胰岛组织病理变化。结果与模型组比较,灌胃组和注射组的血糖水平在给药后1～4周明显下降,而血清胰岛素水平显著升高（P〈0.01）。灌胃组在各时间点的血糖、胰岛素水平与注射组相比,差异无统计学意义（P〉0.05）。HE染色发现,灌胃组和注射组大鼠的胰岛组织病变有所改善。结论重组hGLP-1类似物可降低糖尿病大鼠的血糖、提高血清胰岛素水平。 相似文献
13.
In the fruit fly Drosophila, four insulin genes are coexpressed in small clusters of cells [insulin-producing cells (IPCs)] in the brain. Here, we show that ablation of these IPCs causes developmental delay, growth retardation, and elevated carbohydrate levels in larval hemolymph. All of the defects were reversed by ectopic expression of a Drosophila insulin transgene. On the basis of these functional data and the observation that IPCs release insulin into the circulatory system, we conclude that brain IPCs are the main systemic supply of insulin during larval growth. We propose that IPCs and pancreatic islet beta cells are functionally analogous and may have evolved from a common ancestral insulin-producing neuron. Interestingly, the phenotype of flies lacking IPCs includes certain features of diabetes mellitus. 相似文献
14.
Mitochondrial dysfunction and type 2 diabetes 总被引：1，自引：0，他引：1
Maintenance of normal blood glucose levels depends on a complex interplay between the insulin responsiveness of skeletal muscle and liver and glucose-stimulated insulin secretion by pancreatic beta cells. Defects in the former are responsible for insulin resistance, and defects in the latter are responsible for progression to hyperglycemia. Emerging evidence supports the potentially unifying hypothesis that both of these prominent features of type 2 diabetes are caused by mitochondrial dysfunction. 相似文献
15.
Increased insulin sensitivity and obesity resistance in mice lacking the protein tyrosine phosphatase-1B gene 总被引：1，自引：0，他引：1
Elchebly M Payette P Michaliszyn E Cromlish W Collins S Loy AL Normandin D Cheng A Himms-Hagen J Chan CC Ramachandran C Gresser MJ Tremblay ML Kennedy BP 《Science (New York, N.Y.)》1999,283(5407):1544-1548
Protein tyrosine phosphatase-1B (PTP-1B) has been implicated in the negative regulation of insulin signaling. Disruption of the mouse homolog of the gene encoding PTP-1B yielded healthy mice that, in the fed state, had blood glucose concentrations that were slightly lower and concentrations of circulating insulin that were one-half those of their PTP-1B+/+ littermates. The enhanced insulin sensitivity of the PTP-1B-/- mice was also evident in glucose and insulin tolerance tests. The PTP-1B-/- mice showed increased phosphorylation of the insulin receptor in liver and muscle tissue after insulin injection in comparison to PTP-1B+/+ mice. On a high-fat diet, the PTP-1B-/- and PTP-1B+/- mice were resistant to weight gain and remained insulin sensitive, whereas the PTP-1B+/+ mice rapidly gained weight and became insulin resistant. These results demonstrate that PTP-1B has a major role in modulating both insulin sensitivity and fuel metabolism, thereby establishing it as a potential therapeutic target in the treatment of type 2 diabetes and obesity. 相似文献
16.
Eosinophils sustain adipose alternatively activated macrophages associated with glucose homeostasis 总被引：1，自引：0，他引：1
Wu D Molofsky AB Liang HE Ricardo-Gonzalez RR Jouihan HA Bando JK Chawla A Locksley RM 《Science (New York, N.Y.)》2011,332(6026):243-247
Eosinophils are associated with helminth immunity and allergy, often in conjunction with alternatively activated macrophages (AAMs). Adipose tissue AAMs are necessary to maintain glucose homeostasis and are induced by the cytokine interleukin-4 (IL-4). Here, we show that eosinophils are the major IL-4-expressing cells in white adipose tissues of mice, and, in their absence, AAMs are greatly attenuated. Eosinophils migrate into adipose tissue by an integrin-dependent process and reconstitute AAMs through an IL-4- or IL-13-dependent process. Mice fed a high-fat diet develop increased body fat, impaired glucose tolerance, and insulin resistance in the absence of eosinophils, and helminth-induced adipose tissue eosinophilia enhances glucose tolerance. Our results suggest that eosinophils play an unexpected role in metabolic homeostasis through maintenance of adipose AAMs. 相似文献
17.
采用组织切片和免疫组化技术对大口黑鲈的胰腺进行了组织学观察。经H-E染色和G-醛复红染色了的切片显示:大口黑鲈腹腔中10多个肉眼可见的黄白色颗粒物其实是被一层结缔组织和外分泌胰腺包裹着的胰岛结构,其中最大的一个即为主岛;还有许多肉眼不可见的胰岛结构被埋藏于总胆管的管壁中;肝脏中有外分泌胰腺的存在与分布。过氧化物酶标记的链霉卵白素免疫组化切片和图像分析显示:B细胞主要集中胰岛的中央区;A细胞分布于胰岛的全部。本研究的结论为:大口黑鲈的内分泌胰腺主要分布于总胆管周围,外分泌胰腺除了包裹于胰岛之外也分布于肝脏中,胰腺的分布属于弥散型。 相似文献
18.
Blood vessels supply developing organs with metabolic sustenance. Here, we demonstrate a role for blood vessels as a source of developmental signals during pancreatic organogenesis. In vitro experiments with embryonic mouse tissues demonstrate that blood vessel endothelium induces insulin expression in isolated endoderm. Removal of the dorsal aorta in Xenopus laevis embryos results in the failure of insulin expression in vivo. Furthermore, using transgenic mice, we show that ectopic vascularization in the posterior foregut leads to ectopic insulin expression and islet hyperplasia. These results indicate that vessels not only provide metabolic sustenance, but also provide inductive signals for organ development. 相似文献
19.
Effect of vanadate on elevated blood glucose and depressed cardiac performance of diabetic rats 总被引：28，自引：0，他引：28
The trace element vanadium has an unclear biological function. Vanadate, an oxidized form of vanadium, appears to have an insulin-like action. The effect of vanadate on blood glucose and cardiac performance was assessed in female Wistar rats 6 weeks after they were made diabetic with streptozotocin. When vanadate was administered for a 4-week period to the diabetic rats, their blood glucose was not significantly different from that of nondiabetic controls despite a low serum insulin. In contrast, blood glucose was increased about threefold in the diabetic rats that were not treated with vanadate; these rats also had low insulin levels. Cardiac performance was depressed in the untreated diabetic animals, but the cardiac performance of the vanadate-treated diabetic animals was not significantly different from that of nondiabetic controls. Thus vanadate controlled the high blood glucose and prevented the decline in cardiac performance due to diabetes. 相似文献
20.
Effects of cyclosporine immunosuppression in insulin-dependent diabetes mellitus of recent onset 总被引：19，自引：0，他引：19
C R Stiller J Dupré M Gent M R Jenner P A Keown A Laupacis R Martell N W Rodger B von Graffenried B M Wolfe 《Science (New York, N.Y.)》1984,223(4643):1362-1367
Type I diabetes may be an autoimmune disorder, although the evidence is largely circumstantial. The natural history of the disease after diagnosis includes partial remission in most patients, but only about 3 percent achieve transient insulin independence. beta Cell function, as indicated by the plasma concentration of C-peptide, is lost over 6 to 30 months and islet cell antibodies disappeared over 1 to 2 years. This article describes a pilot study in which 41 patients were treated with the immunosuppressive agent cyclosporine for 2 to 12 months. Of 30 patients treated within 6 weeks of diagnosis, 16 became insulin independent with concentrations of plasma C-peptide in the normal range and decreasing titers of islet cell antibodies. Of 11 patients who entered the study 8 to 44 weeks after diagnosis, two achieved this state. These results indicate that a controlled trial of the effects of cyclosporine in type I diabetes should be conducted. 相似文献