• Title/Summary/Keyword: Insulin secretion

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Roles of Non-cholinergic Intrapancreatic Nerves, Serotonergic Nerves, on Pancreatic Exocrine Secretion in the Isolated Perfused Rat Pancreas

  • Jiang, Zheng Er;Shin, Bich-Na;Kim, In-Hye;Lee, Hyun-Joo;Yong, Jun-Hwan;Lee, Min-Jae;Won, Moo-Ho;Lee, Yun-Lyul
    • The Korean Journal of Physiology and Pharmacology
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    • v.15 no.5
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    • pp.307-312
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    • 2011
  • It has been rereported that axons which display 5-hydroxytryptamine (5-HT) immunoreactivity are abundant in the pancreas and the majority of serotonergic axons terminate within intrapancreatic ganglia, islet and acini. This histological result strongly suggests that intrapancreatic serotonergic nerves could affect to the pancreatic endocrine and exocrine secretion. Thus, this study was aimed to investigate whether intrapancreatic serotonergic nerves could affect pancreatic exocrine secretion and an action mechanism of the intrapancreatic serotonergic nerves. The rats were anesthetized with a single injection of urethane. The median line and the abdominal aorta was carefully dissected and cannulated with PE-50 tubing just above the celiac artery, and then tightly ligated just below the superior mesenteric artery. The pancreatic duct was also cannulated with Tygon microbore tubing. With the addition of serotonin, pancreatic volume flow and amylase output were significantly inhibited electrical field stimulation (EFS). On the other hand, pancreatic volume flow and amylase output were significantly elevated in EFS with the addition of spiperone. EFS application, however, pancreatic volume flow and amylase output had no significant change in cholecystokinin (CCK) alone when serotonin was applied under a 5.6 mM glucose background. Pancreatic volume flow and amylase output under 18 mM glucose background were significantly elevated in CCK plus serotonin than in CCK alone. These data suggest that intrapancreatic serotonergic nerves play an inhibitory role in pancreatic exocrine secretion and an important role in the insulin action or release.

Effects of ethanol-induced p42/44 MAPkinase activity on IGF system in primary cultured rat hepatocytes (흰쥐의 배양된 간세포에서 ethanol에 의해 유도된 p42/44 MAPkinase가 IGF system에 미치는 효과)

  • Lee, Sun-Mi;Kim, Jong-Hoon;Kang, Chang-Won
    • Korean Journal of Veterinary Research
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    • v.46 no.4
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    • pp.315-322
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    • 2006
  • Ethanol abuse is associated with liver injury, neurotoxicity, modulation of immune responses, and increased risk for cancer, whereas moderate ethanol consumption exerts protective effects against liver injury. However, the underlying signal transduction mechanisms of insulin-like growth factors (IGFs) which play an important regulatory role in various metabolism mechanisms are not well understood. We investigated the effects of ethanol-induced p42/44 activity on IGF-I secretion, IGF-I receptor and IGFBP-1 secretion using radioimmunoassay and western blotting in primary cultured rat hepatocytes. The p42/44 activity, IGF-I secretion and IGF-I receptor activity significantly accelerated compared to control at 10 and 30 min after 200 mM ethanol treatment, but then it became suppressed at 180 min. In contrast, IGFBP-1 secretion was inhibited compared to control at 30 min after 200 mM ethanol treatment, but increased at 180 min. The IGF-I secretion, IGF-I receptor and p42/44 activity at 30 min after 200 mM ethanol treatment accelerated with increasing ethanol concentration but IGFBP-1 secretion inhibited (p<0.05). The increased IGF-I secretion, inhibited IGFBP-1 secretion and IGF-IR activity by ethanol-induced temporal p42/44 activity at 30 min after ethanol treatment was blocked by treatment with PD98059. Alcohol dehydrogenase (ADH) inhibitor, 4-methylpyramazole blocked the changes of IGF-I secretion, IGFBP-1 secretion, and IGF-IR activity by ethanol-induced p42/44 activity at 30 and 180 min. Taken together, these results suggest that ethanol is involved in the modulation of IGF-I and IGFBP-1 secretion and IGF-IR activity by p42/44 activity in primary cultured rat hepatocytes. In addition, changing of p42/44 activity by ethanol was caused with ADH.

Induction of insulin receptor substrate-2 expression by Fc fusion to exendin-4 overexpressed in E. coli: a potential long-acting glucagon-like peptide-1 mimetic

  • Kim, Jae-Woo;Kim, Kyu-Tae;Ahn, You-Jin;Jeong, Hee-Jeong;Jeong, Hyeong-Yong;Ryu, Seung-Hyup;Lee, Seung-Yeon;Lee, Chang-Woo;Chung, Hye-Shin;Jang, Sei-Heon
    • BMB Reports
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    • v.43 no.2
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    • pp.146-149
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    • 2010
  • Exendin-4 (Ex-4), a peptide secreted from the salivary glands of the Gila monster lizard, can increase pancreatic $\beta$-cell growth and insulin secretion by activating glucagon-like peptide-1 receptor. In this study, we expressed a fusion protein consisting of exendin-4 and the human immunoglobulin heavy chain (Ex-4/IgG-Fc) in E. coli and explored its potential therapeutic use for the treatment of insulin-resistant type 2 diabetes. Here, we show that the Ex-4/IgG-Fc fusion protein induces expression of insulin receptor substrate-2 in rat insulinoma INS-1 cells. Our findings therefore suggest that Ex-4/IgG-Fc overexpressed in E. coli could be used as a potential, long-acting glucagon-like peptide-1 mimetic.

RELATIONSHIP BETWEEN SOME CIRCULATING HORMONES, METABOLITES AND MILK YIELD IN LACTATING CROSSBRED COWS AND BUFFALOES

  • Jindal, S.K.;Ludri, R.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.7 no.2
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    • pp.239-248
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    • 1994
  • To study the relationship between certain hormones and metabolites and between hormones and milk yield during different stage of lactation, six lactating Karan Swiss cows and six Murrah buffaloes were maintained. Growth hormone, insulin, $T_3$, $T_4$, glucose, BHBA, NEFA and milk yield were studied. Highly negative relationship of growth hormone with insulin and triiodothyronine in cows and marginally negative in buffaloes suggest that insulin and triiodothyronine aid in the process of partitioning of nutrients towards milk production through reducing the demands of nutrients by peripheral tissue. The significant and negative correlation of growth hormone with dry matter intake in both the species suggest that the availability of nutrients from the digestive tract play a role in the regulation of growth hormone secretion. Positive relationship of growth hormone with non esterified fatty acids in both the species suggest that high growth hormone levels may result in fat mobilization and thereby increase the availability of energy precursors for milk synthesis. Insulin was negatively correlated with milk yield and lactose content and positively with milk fat and protein but the degree of relationship varied. In both the species the relationship between triiodothyronine and milk yield was negative and between thyroxine and milk yield was positive. However, it was significant only in cows and not in buffaloes. Thyroxine was positively correlated with beta-hydroxybutyrate and non-esterified fatty acids with milk yield in both the species.

An Update on Prader-Willi Syndrome with Diabetes Mellitus

  • Lee, Ji-Eun
    • Journal of mucopolysaccharidosis and rare diseases
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    • v.2 no.2
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    • pp.35-37
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    • 2016
  • Prader-Willi syndrome (PWS) often develops type 2 diabetes mellitus (T2DM) related to severe obesity. The prevalence of T2DM in adults with PWS (7-20%) exceeds greatly the prevalence in the general population (5-7%). It is uncommon for pre-pubertal children with PWS to develop overt diabetes or glucose intolerance. GH therapy and genotype did not influence the development of altered glucose metabolism. It has been assumed that T2DM in PWS develops as a consequence of morbid obesity and concomitant insulin resistance. However recent studies suggest the relationship between morbid obesity and T2DM development is more complex and appears to differ in PWS subjects compared to non-PWS subjects. PWS patients had relatively lower fasting insulin levels and increased adiponectin levels compared with BMI-matched obese control despite of similar levels of leptin. So PWS children may be protected to some extent form of obesity-associated insulin resistance. Although there's no data, it seems logical to approach diabetes management including weight loss and increased exercise, using similar pharmacological agents as with non-PWS obesity-related diabetes such as metformin or thiazolidinedione, with the introduction of insulin as required. On the other hand, several recent T2DM in PWS case reports suggest favorable outcomes using Glucagon-like peptide 1 (GLP-1) analog with regard to ghrelin reduction, control of glucose and appetite, weight loss and pre-prandial insulin secretion. The role of GLP-1 agonist therapy is promising, but has not yet been fully elucidated.

Changes in the glucose and insulin responses according to high-protein snacks for diabetic patients

  • Yang, Junyoung;Park, Hae Jin;Hwang, Wonsun;Kim, Tae Ho;Kim, Hyeonmok;Oh, Jieun;Cho, Mi Sook
    • Nutrition Research and Practice
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    • v.15 no.1
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    • pp.54-65
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    • 2021
  • BACKGROUND/OBJECTIVES: This study aimed to develop healthy, appetizing high-protein snacks with enhanced isolated soy protein for diabetic patients and determine the blood glucose and insulin response after being consumed by these patients. MATERIALS/METHODS: Thirty adult patients aged between 30 and 75 years, with a ≤ 10-year history of type 2 diabetes and hemoglobin A1c of < 7.5%, were enrolled in this study. They made 3 clinical visits at one-week intervals. The control group consumed 50 g carbohydrates (white bread), whereas the test groups consumed high-protein grain (HP_G) or high-protein chocolate (HP_C) after an 8-hrs fast. Blood (2 ㎤) was drawn at 15, 30, 45, 60, 90, and 120 min before and after consumption to analyze the blood glucose and insulin concentrations. RESULTS: Compared to the commercial snacks, the developed high-protein snacks had below-average calorie, carbohydrate, and fat content and a 2.5-fold higher protein content. In diabetic patients who consumed these snacks, the postprandial blood glucose increased between 15 min and 2 h after consumption, which was significantly slower than the time taken for the blood glucose to increase in the patients who consumed the control food product (P < 0.001). Insulin secretion was significantly lower at 45 min after consumption (P < 0.05), showing that the high-protein snacks did not increase the blood glucose levels rapidly. The incremental area under the curve (iAUC), which indicated the degree of blood sugar and insulin elevation after food intake, was higher in the control group than the groups given the 2 developed snacks (P < 0.001), and there was no significant difference in insulin secretion. CONCLUSIONS: The results of the postprandial blood glucose and insulin response suggest that high-protein snacks are potential convenient sources of high-quality protein and serve as a healthier alternative for patients with type 2 diabetes, who may have limited snack product choices. Such snacks may also provide balanced nutrition to pre-diabetic and obese individuals.

Growth Stimulation and Inhibition of Differentiation of the Human Colon Carcinoma Cell Line Caco-2 with an Anti-Sense Insulin-Like Growth Factor Binding Protein-3 Construct

  • YoonPark, Jung-Han
    • BMB Reports
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    • v.32 no.3
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    • pp.266-272
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    • 1999
  • The insulin-like growth factor (IGF) system consisting of IGF-I, IGF-II, IGF-receptors, and IGF-binding proteins (IGFBP) regulates the proliferation of a variety of cancer cell types. To examine whether a decrease in endogenous IGFBP-3 stimulates proliferation or inhibits differentiation, Caco-2 cells, a human colon adenocarcinoma cell line, were stably transfected with an anti-sense IGFBP-3 expression construct or pcDNA3 vector as control. Accumulation of IGFBP-3 mRNA and secretion of IGFBP-3 into serum-free conditioned medium, 9 days after plating, were significantly lower in Caco-2 cell clones transfected with anti-sense IGFBP-3 cDNA compared to the controls. The anti-sense clones grew at a similar rate to the controls for 8 days after plating, but achieved a higher final density between days 10 and 12. The levels of sucrase-isomaltase mRNA, a marker of enterocyte differentiation of Caco-2 cells, were lower in the anti-sense clones examined on day 9. In conclusion, proliferation of Caco-2 cells can be stimulated by lowering endogenously-produced IGFBP-3.

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Mechanisms underlying diabetes-induced bone loss

  • Ju Han Song;Xianyu Piao;Jeong-Tae Koh
    • International Journal of Oral Biology
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    • v.49 no.2
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    • pp.27-33
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    • 2024
  • Diabetes, a chronic hyperglycemic condition, is caused by insufficient insulin secretion or functional impairment. Long-term inadequate regulation of blood glucose levels or hyperglycemia can lead to various complications, such as retinopathy, nephropathy, and cardiovascular disease. Recent studies have explored the molecular mechanisms linking diabetes to bone loss and an increased susceptibility to fractures. This study reviews the characteristics and molecular mechanisms of diabetes-induced bone disease. Depending on the type of diabetes, changes in bone tissue vary. The molecular mechanisms responsible for bone loss in diabetes include the accumulation of advanced glycation end products (AGEs), upregulation of inflammatory cytokines, induction of oxidative stress, and deficiencies in insulin/IGF-1. In diabetes, alveolar bone loss results from complex interactions involving oral bacterial infections, host responses, and hyperglycemic stress in periodontal tissues. Therapeutic strategies for diabetes-induced bone loss may include blocking the AGEs signaling pathway, decreasing inflammatory cytokine activity, inhibiting reactive oxygen species generation and activity, and controlling glucose levels; however, further research is warranted.

Aging and Gasroenterrogi Changes (노화에 따른 위장관 기능의 변화)

  • 조우균
    • The Korean Journal of Food And Nutrition
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    • v.6 no.3
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    • pp.219-230
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    • 1993
  • This research aims to study the changes In gastrointestinal function attributed to aging In human. The thresholds for recognition and detection of flavors became elevated and salivary gland acinar cells decreased in the old age. But most esophageal function remained relatively Intact. Although gastric emptying time has been slowed with aging, the total intestinal transit time did not differ. Atropic gastritis due to H. pylori in old man decreased secretion of acid and Intrinsic factor and absorbability of calcium and iron. Pancreatic secretion is droned in older persons. Prevalence of gallstones rised with age. Liver size and portal blood flow decreased significantly with age. Mucosal surface area has been reported to be slightly diminished in the aging man. Glucose transporters decreased and Insulin tolerance Increased. Absorption of aromatic amino acid is diminished with age. Dietary protein In that aging human increased fecal nitrogen excretion. Vitamin A tolerance increased. Vitamin D receptor concentration decreased and resistance to 1,25-(OH)2D3 action increased. Permeability of aging small Intestine Increased. Zinc balance dirt not differ Copper absorption appeared not to be significantly affected by age. Neurotensin secretion decreased thus slowed colonic peristaltic movements and Intestinal mucosal growth.

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