Beta cell
From Wikipedia, the free encyclopedia
Beta cells (beta-cells, β-cells) are a type of cell in the pancreas in areas called the islets of Langerhans. They make up 65-80% of the cells in the islets.
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[edit] Function
Beta cells make and release insulin, a hormone that controls the level of glucose in the blood. There is a baseline level of insulin maintained by the pancreas, but it can respond quickly to spikes in blood glucose by releasing stored insulin while simultaneously producing more. The response time is fairly quick, taking approximately 10 minutes.
Apart from insulin, beta cells release C-peptide, a byproduct of insulin production, into the bloodstream in equimolar quantities. C-peptide helps to prevent neuropathy, and other symptoms of diabetes related to vascular deterioration[1]. Measuring the levels of C-peptide can give a practitioner an idea of the viable beta cell mass.[2]
β-cells also produce amylin,[3] also known as IAPP, islet amyloid polypeptide. Amylin functions as part of the endocrine pancreas and contributes to glycemic control. Amylin's metabolic function is now somewhat well characterized as an inhibitor of the appearance of nutrient [especially glucose] in the plasma. It thus functions as a synergistic partner to insulin. Whereas insulin regulates long term food intake, increased amylin decreases food intake in the short term.
[edit] Pathology
- Diabetes mellitus type 1 is caused by the destruction or dysfunction of insulin-producing beta cells by the cells of the immune system.
- In Diabetes mellitus type 2, by contrast, beta cells decline gradually over time, and insulin resistance plays at least as large a role in the disease [4][5]
- Insulinoma is a rare tumor (usually benign) derived from beta cells. It results in recurrent and prolonged attacks of hypoglycemia.
[edit] Research
Much research is being done in the field of beta-cell physiology and pathology. One major research topic is its effects on diabetes. Many researchers are trying to find ways to use these beta-cells to help control or prevent diabetes. A major topic is the replication of adult beta-cells and the application of these to diabetes. The Larry L. Hillblom Islet Research Center at UCLA[6] is a leading research center in the field, within the Diabetes and Endocrinology Research Center[7], directed by Dr. Peter Butler. [8]
A team science effort also exists, known as the Beta Cell Biology Consortium (BCBC).[9] The BCBC is responsible for facilitating interdisciplinary approaches that will advance the understanding of pancreatic islet development and function. The long-term goal of the BCBC is to develop a cell-based therapy for insulin delivery.
[edit] See also
[edit] References
- ^ Y. Ido, A. Vindigni, K. Chang, L. Stramm, R. Chance, W. F. Heath, R. D. DiMarchi, E. Di Cera, J. R. Williamson. 1997. Prevention of Vascular and Neural Dysfunction in Diabetic Rats by C-Peptide. Science, Vol. 277. no. 5325, pp. 563 - 566.
- ^ Hoogwerf B, Goetz F (1983). "Urinary C-peptide: a simple measure of integrated insulin production with emphasis on the effects of body size, diet, and corticosteroids". J Clin Endocrinol Metab 56 (1): 60-7. PMID 6336620.
- ^ Moore C, Cooper G (1991). "Co-secretion of amylin and insulin from cultured islet beta-cells: modulation by nutrient secretagogues, islet hormones and hypoglycemic agents". Biochem Biophys Res Commun 179 (1): 1-9. doi:. PMID 1679326.
- ^ "U.K. prospective diabetes study 16. Overview of 6 years' therapy of type II diabetes: a progressive disease. U.K. Prospective Diabetes Study Group" (1995). Diabetes 44 (11): 1249-58. PMID 7589820.
- ^ Rudenski A, Matthews D, Levy J, Turner R (1991). "Understanding "insulin resistance": both glucose resistance and insulin resistance are required to model human diabetes". Metabolism 40 (9): 908-17. doi:. PMID 1895955.
- ^ The Larry L. Hillblom Islet Research Center
- ^ The DERC Homepage has moved
- ^ Faculty
- ^ Beta Cell Biology Consortium
[edit] External links
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