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1.
Somatostatin: hypothalamic inhibitor of the endocrine pancreas 总被引：32，自引：0，他引：32
D J Koerker W Ruch E Chideckel J Palmer C J Goodner J Ensinck C C Gale 《Science (New York, N.Y.)》1974,184(135):482-484
Somatostatin, a hypothalamic peptide that inhibits the secretion of pituitary growth hormone, inhibits basal insulin secretion in fasted cats and rats. In fasted baboons both basal and arginine-stimulated secretion of insulin and glucagon are inhibited. Somatostatin appears to act directly on the endocrine pancreas. The action is dose-related, rapid in onset, and readily reversed. 相似文献
2.
Circulating somatostatin acts on the islets of Langerhans by way of a somatostatin-poor compartment 总被引：8，自引：0，他引：8
Somatostatin perfused in canine pancreases at 10 to 20 picograms per milliliter or 10 to 20 percent of the pancreatic vein somatostatin concentration inhibited insulin and glucagon secretion. This suggests that the high local concentration of endogenous somatostatin is not in contact with somatostatin receptors of the islets. The integrity of this separation may determine the sensitivity of islet cells to circulating somatostatin. 相似文献
3.
Vitamin D-deficient rats produce [(3)H]1,25-dihydroxyvitamin D(3) from [(3)H]25-hydroxyvitamin D(3) regardless of dietary content of calcium or phosphate. A daily dose of 130 picomoles of 1,25-dihydroxyvitamin D(3) for a period of 5 days reduces production of [(3)H]1,25-dihydroxyvitamin D(3) to essentially zero and stimulates production of [(3)H]24,25-dihydroxyvitamin D(3). A daily dose of 325 picomoles of 25-hydroxyvitamin D(3) has a similar but less dramatic effect. On the other hand, 650 picomoles daily of 24,25-dihydroxyvitamin D(3) given to vitamin D-deficient rats had no effect. Thus it appears that 1,25-dihydroxyvitamin D(3) is an important factor in the regulation of kidney metabolism of 25-hydroxyvitamin D(3). 相似文献
4.
Insulin release from isolated human fetal pancreatic islets 总被引：6，自引：0，他引：6
Pancreases were obtained from five human fetuses 12 to 16 weeks old. The islets of Langerhans were isolated with collagenase, and then incubated with buffer, glucose, tolbutamide, or glucagon added to the medium. The insulin released into the medium was measured by immunoassay. Glucagon produced the only significant increase above base line; glucose and tolbutamide failed to enhance secretion of insulin. The data suggest that isolated human fetal islets of this gestational age develop responsiveness to glucagon earlier than to glucose or tolbutamide. 相似文献
5.
山药多糖对2型糖尿病大鼠降糖机理的研究 总被引：2，自引：0，他引：2
为探讨山药多糖对2型糖尿病的降糖机理,采用高热量饮食结合腹腔注射小剂量链脲佐菌素(STZ)的方法制备试验性2型糖尿病大鼠模型,以不同剂量山药多糖[(100、70和40 mg/(kg.d)]和二甲双胍100 mg/(kg.d)灌胃治疗4周后,检测血清胰岛素及胰高血糖素、己糖激酶(HK)、琥珀酸脱氢酶(SDH)和苹果酸脱氢酶(MDH)的活性。结果表明,与糖尿病模型组比较,山药多糖具有明显的降血糖作用;治疗组HK、SDH、MDH活性显著提高,提示山药多糖对2型糖尿病的治疗机制之一可能是山药多糖提高了糖代谢关键的酶活性。 相似文献
6.
Anomeric specificity of glucose-stimulated insulin release: evidence for a glucoreceptor? 总被引：4，自引：0，他引：4
The effects on insulin secretion of alpha and beta anomers of D-glucose were studied in the in vitro perfused rat pancreas. Both phases of insulin release showed consistent stereospecificity for alpha-glucose; this specificity indicates an action of glucose independent of intracellular glucose metabolism. 相似文献
7.
Administration of methamphetamine or amphetamine to rats and mice produces a rapid increase in the level of immunoassayable plasma insulin not attributable to hyperglycemia. While in the mouse this release of insulin is followed consistently by a profound hypoglycemia, in the rat this response is variable. Studies in vitro demonstrate that insulin is released by a direct effect of methamphetamine on the pancreas. 相似文献
8.
Target cells for 1,25-dihydroxyvitamin D3 in intestinal tract, stomach, kidney, skin, pituitary, and parathyroid 总被引：21，自引：0，他引：21
After mature rats that had been fed on a vitamin D3-deficient diet were injected with tritium-labeled 1,25-dihydroxyvitamin D3, radioactivity became concentrated in nuclei of luminal and cryptal epithelium of the duodenum, jejunum, ileum, and colon; in nuclei of the epithelium of kidney distal tubules including the macula densa, and in podocytes of glomeruli; in nuclei of the epidermis including outer hairshafts and sebaceous glands; and in nuclei of certain cells of the stomach, anterior and posterior pituitary, and parathyroid. These results reveal cell types that contain receptors for 1,25-dihydroxyvitamin D3 or metabolites of this compound both in known or hypothesized target tissues and in tissues that were previously unknown to participate in vitamin D3 metabolism. 相似文献
9.
康世良 《东北农业大学学报》1984,(2)
大量的研究结果证实,硒对维持雏鸡生长和胰腺外分泌机能具有专一的作用。胰腺是雏鸡硒缺乏的靶器官,而骨骼肌、心肌、肝脏和其它组织在维生素E 充足时,不受缺硒的影响。硒缺乏的雏鸡,即使喂给足够的维生素 E,胰腺也发生变性和纤维化。与补硒鸡相比,硒缺乏鸡血清中生育酚较低,粪中的中性脂类和胆汁较多,血清谷草转氨酶活性升高,胰脂酶和胰蛋白酶活性较低。此结果归因于胰腺的变性和脂酶的缺乏,从而降低了脂肪的水解,破坏了脂类和维生素 E 吸收所必需的脂类——胆汁微胶粒的形成。在日粮中加入胆汁酸,仅仅部分地改善脂肪的消化和维生素 E 的吸收。补饲游离的脂肪酸和单油酸甘油脂,增加了鸡的维生素E 吸收和存活时间,但不能防止胰腺的纤维化。生物化学研究还表明,酶原活性降低,溶酶体酶中的组织蛋白酶和酸性磷酸酶活性升高。硒是谷胱甘肽过氧化物酶(GSH—Px)的重要组分,此酶与鸡的渗出性素质相关;而且日粮中的硒含量与血清中 GSH—Px 活性高度相关,但是,Contor 报道,GSH—Px 与胰腺萎缩没有相关性。组织化学的研究揭示了由于巨噬细胞的侵润,而导致溶酶体的酶增多。在变性的胰腺中未获得溶酶体破坏的证据,由此证明,硒防止胰腺纤维化的作用,不在于保护胰腺细胞中溶酶体的膜。胰腺变性的病理组织学损伤,开始是在胰腺细胞内形成空泡和透明体,胰腺泡成带现象消失。其次,在胰腺泡之间出现成纤维细胞,全部细胞质基本上都皱缩了,因而扩大了胰腺泡的中央腔。最后,胰腺泡呈现由小的浓染的核所组成的细胞轮,并完全被纤维组织包围。内分泌胰岛显得非常明显,但内分泌机能不紊乱,β-胰岛细胞也不受缺硒的影响。尽管组织学观察到透明体,但线粒体的呼吸机能未受影响。胰腺的组织学检查证明,大麦和硒蛋氨酸是最有效的硒源,就予防胰腺变性的效力而言,硒蛋氮酸是亚硒酸钠和硒代胱氨酸的四倍。严重的胰腺变性常常继发渗出性素质,在防止鸡的渗出性素质中,植物源性硒的生物学活性比动物源性高,硒代胱氨酸比蛋氨酸活性大,但不如亚硒酸钠有效。 相似文献
10.
Pancreatic beta-cell web: its possible role in insulin secretion 总被引：31，自引：0，他引：31
A cortical band of fine microfilaments is consistently observed in the beta cells of the rat pancreas. Alteration of this cell web by cytochalasin B is associated with an enhancement of glucose-induced secretion of insulin by isolated islets. The microfilamentous web of the beta cell may play an important role in the emiocytosis of insulin secretory granules, by controlling their access to the cell membrane. 相似文献
11.
刘济五 《中国农业大学学报》1984,(2):195-202
通过五例大猫熊胰的大体解剖学观察,本文对胰的外形、分叶、位置关系,胰的门静脉环、主胰管和副胰管均给以系统描述。大猫熊胰的脉管比较复杂,供应胰的动脉有:肝总动脉分出的胃右动脉的胰支或胃十二指肠动脉的胰支;脾动脉的胰支以及肠系膜前动脉的胰支一胰十二指肠后动脉,后者仅分布于胰,可称为胰右叶后动脉。胰的静脉有:胰右叶后静脉,左叶静脉,胃网膜右静脉,胰十二指肠前静脉。 相似文献
12.
Beta-adrenergic mechanism of insulin-induced adrenocorticotropin release from the anterior pituitary 总被引：4，自引：0，他引：4
E Mezey T D Reisine M J Brownstein M Palkovits J Axelrod 《Science (New York, N.Y.)》1984,226(4678):1085-1087
Intraperitoneal administration of insulin to control rats and to rats with pituitary stalk transections or with lesions of the median eminence resulted in increased plasma adrenocorticotropin (ACTH) levels. The insulin-induced stimulation of ACTH release was blocked in both the control and lesioned animals by prior treatment with either the beta-adrenergic antagonist propranolol or the glucocorticoid analog dexamethasone. The direct application of insulin to primary cultures of the anterior pituitary did not evoke ACTH release or affect the maximal ability of corticotropin-releasing factor or epinephrine to stimulate ACTH secretion. The results suggest that insulin stimulates ACTH release by a mechanism in which catecholamines of peripheral origin act directly on the anterior pituitary. 相似文献
13.
Control of experimental diabetes mellitus in rats by transplantation of fetal pancreases 总被引：4，自引：0，他引：4
Experimental diabetes mellitus in young adult Lewis rats was successfully treated by transplantation of fetal pancreases from syngeneic fetuses. Complete or partial control lasting up to 165 days was achieved in 64 percent of recipients by using two to three pancreases of fetal age (15 to 18(1/2) days) placed under each kidney capsule. Islets of Langerhans without exocrine elements were present in the transplants. 相似文献
14.
Pancreatic secretion by nonparallel exocytosis: potential resolution of a long controversy 总被引：1，自引：0，他引：1
The idea that pancreatic digestive enzyme secretion can occur in a nonparallel manner has been controversial because of its presumed incompatibility with the exocytosis secretory mechanism. Correlation and regression analysis of enzyme output by the rabbit pancreas after it is stimulated with cholecystokinin and chymodenin revealed that digestive enzymes are secreted in a highly linked fashion, compatible with exocytosis and with nonparallel secretion. Thus, exocytosis and nonparallel secretion are not contradictory processes, but rather nonparallel secretion is due to exocytosis from heterogeneous sources within the pancreas. 相似文献
15.
Alpha-aminoisobutyric acid transport in hepatoma cells in culture was increased by insulin but not by hydrocortisone. Both of these agents induce tyrosine aminotransferase activity in this system. The apparent increase in alpha-aminoisobutyric acid transport and tyrosine aminotransferase activity produced by glucagon is probably caused by insulin contamination. Insulin did not increase transport in this system until after tyrosine aminotransferase activity had reached maximum levels. The mechanisms underlying increased alpha-aminoisobutyric acid transport appear to differ from those for tyrosine aminotransferase induction with hydrocortisone despite their close association in previous whole animal experiments. 相似文献
16.
大肠阻塞马骡静脉糖耐量与胰岛素和胰升糖素应答反应的试验研究 总被引：2，自引：0，他引：2
苏雷 《甘肃农业大学学报》1994,(3)
本研究对１５例大肠阻塞马骡进行了静脉糖耐量试验（ＩＶＧＴＴ），检测了血糖的动态变化与血浆胰岛素和胰升糖素的应答反应和尿糖，结果表明，大肠阻塞马骡血糖升高；血浆胰岛素和胰升糖素增加；糖代谢时间延迟，血浆胰岛素和胰升糖素清除时间延长，治疗马骡大肠阻塞不宜补糖。 相似文献
17.
【目的】采用real-time PCR方法检测体外激素处理对奶牛乳腺上皮细胞FcRn（neonatal Fc receptor,FcRn）mRNA表达的影响。【方法】在乳腺上皮细胞培养液中添加不同浓度胰高血糖素（0.01、0.1和1 μmol•L-1）、胰岛素（0.005、0.1和0.5 μmol•L-1）、甲状腺素T4（0.01、0.1和1 μmol•L-1）,体外培养并收集细胞,提取细胞mRNA后,利用real-time PCR检测FcRn mRNA的相对丰度。【结果】在一定添加剂量范围内,随着添加剂量的增加,甲状腺素和胰高血糖素能够显著地促进FcRn mRNA表达量升高（P＜0.05）,胰岛素在添加量为0.005 μmol•L-1和0.5 μmol•L-1时FcRn mRNA的表达量低,但在0.1 μmol•L-1添加时表达量显著升高（P＜0.05）。【结论】添加外源胰岛素、胰高血糖素和甲状腺素能够影响FcRn mRNA的表达,为进一步研究乳腺内FcRn受体变化以及影响因素提供了依据。 相似文献
18.
The binding constants and the number of binding sites for insulin, glucagon, epinephrine, cyclic adenosine monophosphate, and calcium ions for the plasma membrane of rat liver were determined by Scatchard plots. The plots are biphasic or multiphasic, an indication of at least two types of binding sites for each ligand. At least three types of binding sites were found for insulin. In the concentration range of 10(-6) to 10(-8) molar, glucagon, epinephrine, and hydro-cortisone increased calcium ion binding to the plasma membrane, whereas insulin decreased this binding. At hormone concentrations of 10(-6) to 10(-7) molar, glucagon was the most effective in increasing calcium binding, but at a hormone concentration of 10(-8) molar, hydrocortisone was the most effective in stimulating calcium binding. Adenosine triphosphate reversed the effect of insulin and inhibited the effect of the other hormones. These studies suggest a relation between hormones and calcium with respect to membrane structure and function. 相似文献
19.
Kodama S Kühtreiber W Fujimura S Dale EA Faustman DL 《Science (New York, N.Y.)》2003,302(5648):1223-1227
Nonobese diabetic (NOD) mice are a model for type 1 diabetes in humans. Treatment of NOD mice with end-stage disease by injection of donor splenocytes and complete Freund's adjuvant eliminates autoimmunity and permanently restores normoglycemia. The return of endogenous insulin secretion is accompanied by the reappearance of pancreatic beta cells. We now show that live donor male or labeled splenocytes administered to diabetic NOD females contain cells that rapidly differentiate into islet and ductal epithelial cells within the pancreas. Treatment with irradiated splenocytes is also followed by islet regeneration, but at a slower rate. The islets generated in both instances are persistent, functional, and apparent in all NOD hosts with permanent disease reversal. 相似文献
20.
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