330 likes | 706 Views
Control of blood glucose. Normal glucose levels are kept within strict limits. Glucose regulation in healthy people. Kick-in when blood glucose levels deviate 20% from set-point. Key players in glucose homeostasis. Pancreas (α and β cells: Islets of Langerhans) Liver Muscles Fat
E N D
Glucose regulation in healthy people • Kick-in when blood glucose levels deviate 20% from set-point
Key players in glucose homeostasis • Pancreas (α and β cells: Islets of Langerhans) • Liver • Muscles • Fat • (all tissues…) • Insulin • Glucagon • (adrenaline) • (steroids) • (growth hormone)
Hormones act on: • Liver • Muscle • Fat • Brain
Insulin optimises glucose uptake by cells NB: The BRAIN and the LIVER don’t need GLUT4 for glucose uptake
Insulin is an anabolic hormone • Primary targets of insulin are liver, fat and muscle cells (but acts on all tissues) • Drives glucose into cells, promotes glucose uptake by muscle, fat and other tissues through facilitated diffusion (GLUT4 protein channel). • Stimulates conversion of glucose to glycogen in liver and in muscles • Inhibits fat breakdown (promotes fat synthesis) • Stimulates amino acid uptake and protein synthesis • Insulin receptors in the hypothalamus promote satiety: the appetite centre has an insulin-driven ‘off’ button…
Glucagon release is stimulated by LOW plasma glucose Released from alpha cells in response to: • Low plasma glucose • Protein-rich meal (high levels of aa’s in blood) • Exercise
Glucagon is a catabolic hormone: released when glucose levels are LOW
Additional effects of glucagon • Liver breaks glycogen down into glucose • Gluconeogenesis occurs from building blocks in the liver • Mild promotion of fat breakdown • Also involved in appetite regulation in the hypothalamus
Glucose regulation in healthy people • Kick-in when blood glucose levels deviate 20% from set-point
Symptoms of diabetes Type 1 • 10% of diabetes patients • ‘Childhood diabetes’ • Toilet • Thirst • Thinner • Tired Type 2 • 90% of diabetes patients • May be influenced by obesity • May be influenced by genetic factors • May be slow onset symptoms • Often undiagnosed for up to 10 years
Complications of diabetes There are many serious potential complications of chronic diabetes, including: • Chronic skin infections • Eye problems and potential blindness from glaucoma (bui;ld up of pressure in the eye) • Nerve damage (often leads to amputations) • High blood pressure, leading to strokes, heart attacks, kidney damage…
Management of Type 1 diabetes • Insulin treatment • ‘Islet ‘ transplants • ‘Vaccine’ to prevent auto-immune destruction of the pancreas
Management of type 2 diabetes • The first-line of treatment is WEIGHT LOSS, dietary control and exercise • Recommended diets are high fibre, low fat • …’diabetes superfoods’….