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10 Cards in this Set
- Front
- Back
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introduction of type I DM
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- accounts for 10-15% of all DM
- char. by hyperglycemia - propensity to develop DKA (ketoacidosis) - may occur at any age, mostly before 30 - peak age is 10 - 14 |
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islet volume and numbers
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- 1 mil islet cells, few scattered among the duct system of pancreas.
- contains 4 types of cells |
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4 types of islet cells
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1. B cells
2. a cells 3. gamma cells 4. PP cells |
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a cells
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more on periphery, 20% cells, elaborate glucagon, which stimluates the liver to begin gluconeogenesis when there is low plasma glu
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B cells
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derived for endoderm. found anywhere along the pancreatic duct system. first evident in embryos in 10 weeks. 70% of cells. secrete and release insulin from dense core vesicals in response to increase in plasma glucose
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gamma cells
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- represent 5-10% of the islet cells
- contain somatostatin which suppresses both insulin and glucagon |
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PP cells
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- 1-2%
- secrete polypeptides that stimulate gastri and enteric secretions |
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insulin acts in glu metabolism thru the following processes
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1. uptake and utilization by cells for the body esp. peripheral tissues such as gut, fat, and muscle
2. glu production/storage in the liver |
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insulin production is solely by B cells of the islet
(what happens before diabetes becomes clinical) |
- DNA encodes the base prs for the transcription to mRNA
- mRNA binds to ribosomal RNA in RER - Translation goes from mRNA to a sequence of AA - post-transitional modifications occur in the golgi apparatus - autoimmunity attacks B cells - B mass declines - Diabetes is when 80% B cell mass is destroyed |
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Stages of first years of diabetes
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- honeymoon phase - first 2 yrs - decreased need for insulin
- preproinsulin - RER - translation - disulfide bonding makes alpha and beta subunits stick together - endopeptidase - in the golgi leads to cleavage of the C-peptides - insulin is stored w/ equimolar conc of C peptides in granules - NO C - PEPTIDES = NO ENDOGENOUS INSULIN |
