Talk:Endocrine - Pancreas Development
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Cite this page: Hill, M.A. (2024, April 16) Embryology Endocrine - Pancreas Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Endocrine_-_Pancreas_Development |
2010
Elevated glucose induces congenital heart defects by altering the expression of tbx5, tbx20, and has2 in developing zebrafish embryos
Liang J, Gui Y, Wang W, Gao S, Li J, Song H. Birth Defects Res A Clin Mol Teratol. 2010 Jun;88(6):480-6.
BACKGROUND: Maternal diabetes increases the risk of congenital heart defects in infants, and hyperglycemia acts as a major teratogen. Multiple steps of cardiac development, including endocardial cushion morphogenesis and development of neural crest cells, are challenged under elevated glucose conditions. However, the direct effect of hyperglycemia on embryo heart organogenesis remains to be investigated.
METHODS: Zebrafish embryos in different stages were exposed to D-glucose for 12 or 24 hr to determine the sensitive window during early heart development. In the subsequent study, 6 hr post-fertilization embryos were treated with either 25 mmol/liter D-glucose or L-glucose for 24 hr. The expression of genes was analyzed by whole-mount in situ hybridization.
RESULTS: The highest incidence of cardiac malformations was found during 6-30 hpf exposure periods. After 24 hr exposure, D-glucose-treated embryos exhibited significant developmental delay and diverse cardiac malformations, but embryos exposed to L-glucose showed no apparent phenotype. Further investigation of the origin of heart defects showed that cardiac looping was affected earliest, while the specification of cardiac progenitors and heart tube assembly were complete. Moreover, the expression patterns of tbx5, tbx20, and has2 were altered in the defective hearts.
CONCLUSIONS: Our data demonstrate that elevated glucose alone induces cardiac defects in zebrafish embryos by altering the expression pattern of tbx5, tbx20, and has2 in the heart. We also show the first evidence that cardiac looping is affected earliest during heart organogenesis. These research results are important for devising preventive and therapeutic strategies aimed at reducing the occurrence of congenital heart defects in diabetic pregnancy.
PMID: 20306498 http://www.ncbi.nlm.nih.gov/pubmed/20306498
Fetal topographical anatomy of the pancreatic head and duodenum with special reference to courses of the pancreaticoduodenal arteries
Jin ZW, Yu HC, Cho BH, Kim HT, Kimura W, Fujimiya M, Murakami G. Yonsei Med J. 2010 May;51(3):398-406.
PURPOSE: The purpose of this study is to provide better understanding as to how the "double" vascular arcades, in contrast to other intestinal marginal vessels, develop along the right margin of the pancreatic head. MATERIALS AND METHODS: In human fetuses between 8-30 weeks, we described the topographical anatomy of the vessels, bile duct, duodenum as well as the ventral and dorsal primordia of the pancreatic head with an aid of pancreatic polypeptide immunohisto-chemistry. RESULTS: The contents of the hepatoduodenal ligament crossed the superior side of the pylorus. Moreover, the right hepatic artery originating from the superior mesenteric artery ran along the superior aspect of the pancreatic head. An arterial arcade, corresponding to the posterior pancreaticoduodenal arteries, encircled the superior part of the pancreatic head, whereas another arcade, corresponding to the anterior pancreaticoduodenal arteries, surrounded the inferior part. The dorsal promordium of the pancreas surrounded and/or mixed the ventral primordium at 13-16 weeks. Thus, both arterial arcades were likely to attach to the dorsal primordium. CONCLUSION: The fetal anatomy of the pancreaticoduodenal vascular arcades as well as that of the hepatoduodenal ligament were quite different from adults in topographical relations. Thus, in the stage later than 30 weeks, further rotation of the duodenum along a horizontal axis seemed to be required to move the pylorus posterosuperiorly and to reflect the superior surface of the pancreatic head posteriorly. However, to change the topographical anatomy of the superior and inferior arterial arcades into the final position, re-arrangement of the pancreatic parenchyma might be necessary in the head.
PMID: 20376893 http://www.ncbi.nlm.nih.gov/pubmed/20376893
http://www.eymj.org/search.php?where=aview&id=128080&code=0069YMJ&vmode=AFTR
2009
Remodelling sympathetic innervation in rat pancreatic islets ontogeny
Cabrera-Vásquez S, Navarro-Tableros V, Sánchez-Soto C, Gutiérrez-Ospina G, Hiriart M. BMC Dev Biol. 2009 Jun 17;9:34. PMID: 19534767
http://www.ncbi.nlm.nih.gov/pubmed/19534767
- "Adult pancreatic β cells secrete insulin in response to an increase in extracellular glucose. At birth, this response is not fully developed as neonate β-cells are insensitive to glucose and synthesize and secrete less insulin than adults [1]. Pancreatic islets are innervated by autonomic fibres. In particular, sympathetic neural cell bodies are located in the superior mesenteric and celiac ganglia and are components of the splanchnic nerve and parasympathetic innervation comes from the vagus nerve [2]."
Conclusion The results suggest that NGF signalling play an important role in the guidance of blood vessels and sympathetic fibres toward the islets during foetal and neonatal stages and could also preserve innervation at later stages of life.
1. Navarro-Tableros V, Fiordelisio T, Hernandez-Cruz A, Hiriart M: Physiological development of insulin secretion, calcium channels, and GLUT2 expression of pancreatic rat beta-cells.
Am J Physiol Endocrinol Metab 2007, 292(4):E1018-1029.
2. Salvioli B, Bovara M, Barbara G, De Ponti F, Stanghellini V, Tonini M, Guerrini S, Cremon C, Degli Esposti M, Koumandou M, et al.: Neurology and neuropathology of the pancreatic innervation. Jop 2002, 3(2):26-33
