The Experts below are selected from a list of 3630 Experts worldwide ranked by ideXlab platform
Yan Huang - One of the best experts on this subject based on the ideXlab platform.
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cholesterol esterase biosynthesis in rat pancreatic ar42j cells post transcriptional activation by Gastric Hormones
Journal of Biological Chemistry, 1991Co-Authors: Yan HuangAbstract:Abstract This study used the rat pancreatoma AR42J as a model system to investigate the possible regulation of cholesterol esterase biosynthesis in pancreas. Initial experiments were performed to verify the synthesis of pancreatic cholesterol esterase by the AR42J cells. Results indicated that this pancreatoma cell line synthesized two forms of cholesterol esterase (Mr = 71,000 and 74,000). The 74-kDa protein is most likely the precursor protein, and the 71-kDa protein is the matured enzyme secreted by the AR42J cells. The synthesis and secretion of cholesterol esterase were stimulated 2-5-fold by incubating the cells with 0.5-4 nM of cholecystokinin or 0.5-2 nM of secretin. Analysis of the RNA isolated from the hormone-stimulated cells revealed that stimulation of cholesterol esterase biosynthesis was not due to an increase in cholesterol esterase mRNA. Furthermore, inhibition of transcription with actinomycin D has no effect on the hormone-induced cholesterol esterase biosynthesis. Therefore, the mechanism of hormone stimulation was not dependent on de novo RNA synthesis. In vitro translation studies showed that the cholesterol esterase mRNA isolated from stimulated AR42J cells were translated more efficiently than those from control cells. Thus, the increased cholesterol esterase biosynthesis induced by Gastric Hormones was most likely mediated by posttranscriptional modification of the cholesterol esterase mRNA.
Weizhen Zhang - One of the best experts on this subject based on the ideXlab platform.
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regulation of Gastric Hormones by systemic rapamycin
Peptides, 2010Co-Authors: Jing Zhao, Xinxin Xiang, Li Ding, Youfei Guan, Xian Wang, Chaoshu Tang, Yi Zhu, Nanping Wang, Michael Mulholland, Weizhen ZhangAbstract:The mammalian target of rapamycin (mTOR), an evolutionarily conserved serine-threonine kinase, is an intracellular fuel sensor critical for cellular energy homeostasis. Gastrointestinal endocrine cells play a vital role in the regulation of energy balance by secreting Hormones that inform the brain about energy supply. Here we showed the localization of mTOR signaling molecules in more than 90% of Gastric ghrelin cells and 36±3% of gastrin cells, while no somatostatin-positive cell showed phospho-S6K1 immunoreactivity. Inhibition of mTOR significantly stimulated expression of Gastric ghrelin mRNA and protein, and the concentration of plasma ghrelin (2.06±0.34 ng/ml vs. 12.53±3.9 ng/ml, p<0.05), inhibited gastrin synthesis and secretion (75.01±6.71 pg/ml vs. 54.04±3.65 pg/ml, p<0.05), but had no effect on somatostatin production (165.2±25.07 pg/ml vs. 178.9±29.14 pg/ml, p=0.73). Gastric mTOR is a Gastric sensor whose activity is linked to the differential regulation of Gastric hormone production and release.
Hiroyuki Kuwano - One of the best experts on this subject based on the ideXlab platform.
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effect of duodenectomy on Gastric motility and Gastric Hormones in dogs
Annals of Surgery, 2001Co-Authors: Hideki Suzuki, Erito Mochiki, Norihiro Haga, Tatsuo Shimura, Zen Itoh, Hiroyuki KuwanoAbstract:The duodenum occupies a strategic anatomical position in the upper digestive tract and is intimately involved in the coordination of various functions of the upper gut. It influences Gastric empting, 1 pancreatic and biliary secretion, 2 and the organization and initiation of Gastric motor patterns 3,4 by invoking hormonal and neural mechanisms. Others have confirmed these findings. 5–7 Tanaka and Sarr 8 reported that duodenectomy disrupts not only the coordination of Gastric and intestinal migrating motor complexes (MMC) but also the coordination between interdigestive motility and pancreatic secretion, and it abolishes the interdigestive cyclic variations in plasma motilin and pancreatic polypeptide (PP) levels. 9 The release of PP appears to be regulated by a complex interplay between neural input (from the vagus) and humoral factors that originate from the upper gut. 10,11 The duodenum also plays an important role by regulating the release of certain pancreatic Hormones. For example, intraduodenal glucose administration causes the release of more insulin than does intravenous glucose administration. This response is in part due to the release of Gastric inhibitory polypeptide (GIP), a putative regulatory hormone found in the duodenum and to some extent the upper jejunum. 12 GIP therefore has a stimulatory or “incretin” effect on insulin release. Motilin, a 22-amino-acid residue polypeptide, 13 is produced in motilin cells, which are scattered throughout the mucosal epithelium of the upper small intestine, like the GIP-producing cells. 14,15 Recently, we have shown that plasma insulin and plasma motilin concentrations fluctuated simultaneously in close association with spontaneous phase III contractions during the interdigestive state. In the dog, the cyclic change in insulin release appears to be controlled by motilin by means of vagal, cholinergic, muscarinic pathways involving 5-hydoroxytryptamine3 (5-HT3) receptors. 16 To date, most studies have focused on pancreatic exocrine secretion, 3–6,9 and there have been no reports on the relation between motilin and insulin in duodenectomized dogs. The aims of the present study, therefore, were to determine whether duodenectomy disrupts the coordination between interdigestive insulin secretion and gastrointestinal motility, and to determine whether alternations of plasma motilin levels accompany changes in insulin secretion and gastrointestinal motility after duodenectomy. In addition, we investigated the effect of exogenous motilin administration on insulin release and gastrointestinal motor activity in dogs after total duodenectomy. Measurements were made of interdigestive insulin secretion, gastrointestinal motility, and plasma concentration of motilin in normal dogs and in dogs that had undergone total duodenectomy.
Arnljot Tveit - One of the best experts on this subject based on the ideXlab platform.
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the post prandial pattern of gut Hormones is related to magnitude of weight loss following Gastric bypass surgery a case control study
Scandinavian Journal of Clinical & Laboratory Investigation, 2014Co-Authors: Tom Gerner, Odd Erik Johansen, Mona Olufsen, Peter A Torjesen, Arnljot TveitAbstract:AbstractBackground. The mechanisms of weight loss after Gastric bypass, including the role of Gastric Hormones, are still not completely understood. While postprandial releases of peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) increase post-surgery and ghrelin usually is reduced, their relationship to the magnitude of the weight loss is still obscure. We explored if differing weight loss after Roux Y Gastric bypass (RYGB) in morbidly obese were associated with differing postprandial hormonal release. Methods. We compared patients with large (> 40%) or moderate (< 25%) weight loss three years following RYGP surgery, and an obese control group scheduled for RYGB (six in each group). A 300 kcal mixed meal test was given with blood sampling before and thereafter at 30-min intervals in 180 min. Peak and incremental area under the curve (iAUC) were calculated to characterize postprandial responses. Results. Early postprandial GLP-1 response were significantly higher in the RYGB groups than in the controls...
Jing Zhao - One of the best experts on this subject based on the ideXlab platform.
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regulation of Gastric Hormones by systemic rapamycin
Peptides, 2010Co-Authors: Jing Zhao, Xinxin Xiang, Li Ding, Youfei Guan, Xian Wang, Chaoshu Tang, Yi Zhu, Nanping Wang, Michael Mulholland, Weizhen ZhangAbstract:The mammalian target of rapamycin (mTOR), an evolutionarily conserved serine-threonine kinase, is an intracellular fuel sensor critical for cellular energy homeostasis. Gastrointestinal endocrine cells play a vital role in the regulation of energy balance by secreting Hormones that inform the brain about energy supply. Here we showed the localization of mTOR signaling molecules in more than 90% of Gastric ghrelin cells and 36±3% of gastrin cells, while no somatostatin-positive cell showed phospho-S6K1 immunoreactivity. Inhibition of mTOR significantly stimulated expression of Gastric ghrelin mRNA and protein, and the concentration of plasma ghrelin (2.06±0.34 ng/ml vs. 12.53±3.9 ng/ml, p<0.05), inhibited gastrin synthesis and secretion (75.01±6.71 pg/ml vs. 54.04±3.65 pg/ml, p<0.05), but had no effect on somatostatin production (165.2±25.07 pg/ml vs. 178.9±29.14 pg/ml, p=0.73). Gastric mTOR is a Gastric sensor whose activity is linked to the differential regulation of Gastric hormone production and release.