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Unformatted text preview: w can insulin cause increased uptake of glucose? ....show movie: Text ! http://research.imb.uq.edu.au/~l.rathbone/glut4/flash/glut4.swf Cellular effects of insulin:
•Stimulates glucose uptake by GLUT-4
•Stimulates glycogen synthesis
•Stimulates fatty acid synthesis
51 52 How can insulin cause increased uptake of glucose? 41 Diabetes Mellitus • Diabetes (Greek: διαβήτης = "passing through," or "siphon")
• excessive urine production
• coined by Aretaeus of Cappadocia,
physician in ancient Greece Text • Mellitus (Latin = “sweet taste”).
• glucose in urine and blood
• Added by Thomas Willis, English
physician (1621-1675) Insulin triggers the exocytosis of intracellular vesicles
containing the GLUT-4 transporters
This results in an increased number of GLUT-4 molecules
in the plasma membrane
53 41 Diabetes Mellitus: Epidemiology
• Worldwide: at least 171 million people suffer from
diabetes 54 41 Diabetes Mellitus • Before 1920s, diabetes mellitus was a fatal disease. • United States: !
! 20.8 million people have been diagnosed with diabetes
! about 6.2 million people undiagnosed (estimate,
American Diabetes Association)!
! estimated costs: $132 billion/year! • Weakness, lethargy, dramatic loss of body mass. • Cells not taking up glucose use fat and protein for fuel,
resulting in the body’s wasting away and tissue and
organ damage. ! 5%–10% of diabetes cases in North America are type
1, with the rest being type 2 55 56 41 Acute complication of D.M.: Diabetic Ketoacidosis 41 Acute complication of D.M.: Diabetic Hypoglycemia • Lack of insulin
• No uptake of blood glucose by cells
• Cells use fat + protein for energy • High blood glucose levels • Liver switches to “starvation
metabolism”: makes ketone
bodies • Glucose and ketone
bodies cause high blood
osmolality: forces water
out of cells • Acidic ketone bodies lower blood
pH: “Ketoacidosis” • Diabetic Hypoglycemia
• Can occur if insulin-treatment “overshoots”
• Lack of blood glucose can lea...
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- Winter '08