The effects of 8-N-N-diethylamino octyl 3,4,5-trimethoxybenzoate (TMB-8) and trifluoperazine (TFP) on the early phase (10 min) of the release of pancreatic hormones from isolated rat islets were investigated. TMB-8 and TFP stimulated insulin, glucagon, and somatostatin release in a dose-dependent manner at a low glucose concentration (2.5 mM). The levels of glucagon and somatostatin release were also stimulated by these two agents at a high glucose concentration (10 mM). Their effects were independent of external calcium ion level. These two agents did not modify insulin release at the high glucose concentration. The stimulative effects of the two agents on the release of these hormones were partially suppressed when the islets were pretreated with 6-hydroxydopamine (6-OHDA), a chemical adrenergic denervator that acts at nerve endings. In this situation, the norepinephrine (NE) released from pancreatic islets decreased to 44% of that of non-treated islets (P less than 0.01). The addition of NE (10(-9) M) to the incubation medium increased insulin, glucagon, and somatostatin secretion by 20-30% over control levels (P less than 0.05). In conclusion, the early phase of pancreatic hormone release was stimulated by TMB-8 and TFP. Our results strongly suggest that these two drugs could be mediated by the NE released from nerve endings in the islets.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0168-8227(89)90033-8 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Single-cell profiling of the amphioxus digestive tract reveals conservation of endocrine cells in chordates.
Sci Adv
December 2024
Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Despite their pivotal role, the evolutionary origins of vertebrate digestive systems remain enigmatic. We explored the cellular characteristics of the amphioxus () digestive tract, a model for the presumed primitive chordate digestive system, using bulk tissue companioned with single-cell RNA sequencing. Our findings reveal segmentation and a rich diversity of cell clusters, and we highlight the presence of epithelial-like, ciliated cells in the amphioxus midgut and describe three types of endocrine-like cells that secrete insulin-like, glucagon-like, and somatostatin-like peptides.
View Article and Find Full Text PDFA Rare and Aggressive Case of Malignant Insulinoma.
Cureus
November 2024
Department of Internal Medicine, Centro Hospitalar Tondela-Viseu, Viseu, PRT.
Insulinomas are rare pancreatic neuroendocrine tumors (NETs) characterized by autonomous insulin secretion leading to hypoglycemia. Malignant insulinomas are defined by the presence of metastases and present significant therapeutic challenges due to limited treatment options. We report the case of a 69-year-old woman with a two-month history of neuroglycopenic symptoms, including morning headaches, blurred vision, palpitations, and sweating, which were alleviated by sugar intake.
View Article and Find Full Text PDFArticle Synopsis
- A four-year-old girl experienced persistent hypoglycemia shortly after birth and was diagnosed with congenital hyperinsulinism due to genetic mutations in the ABCC8 gene.
- She did not respond to typical treatments like oral diazoxide but showed improvement with subcutaneous somatostatin injections.
- At age three and a half, her treatment was changed to a long-acting somatostatin analogue, leading to better blood sugar control, normal growth, and the ability to stop tube feeding.
Imaging human pancreatic endocrinogenesis during early prenatal life.
Diabetes
November 2024
Institut Cochin, CNRS, Inserm, Université Paris Cité, Paris, France.
Murine pancreatic endocrinogenesis has been extensively studied, but human data remain scarce due to limited sample availability. Here, we first built a large collection of human embryonic and fetal pancreases covering the first trimester of pregnancy to explore human endocrinogenesis. Using an experimental pipeline combining in toto staining, tissue clearing, and light-sheet fluorescence microscopy, we show that insulin+, glucagon+, and somatostatin+ cells appear simultaneously at Carnegie Stage (CS) 16.
View Article and Find Full Text PDFA double knockout for zinc transporter 8 and somatostatin in mice reveals their distinct roles in regulation of insulin secretion and obesity.
Genes Nutr
November 2024
Graduate Group of Nutritional Biology, Department of Nutrition, University of California at Davis, One Shields Ave, Davis, CA, 95616, USA.
Background: Both zinc transporter 8 (ZnT8) and somatostatin (Sst) play crucial roles in the regulation of insulin and glucagon secretion. However, the interaction between them in controlling glucose metabolism was not well understood. The aim of this study was to explore the interactive effects of a double knockout of Znt8 and Sst on insulin and glucose metabolism in mice.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!