生物主題報告Insulin and diabetis
B9902070 湯文誠 B9902090 蔡翔霖
Introduction of Insulin
• A hormone released from pancreas
• Regulates carbohydrate and fat metabolism
• Takes up glucose, storing it as glycogen
hexamers
disulfide bonds
Structure of insulin
The endogenous production of insulin is regulated in several steps along the synthesis pathway:
1.At transcription from the insulin gene
2.In mRNA stability 3.At the mRNA translation 4.In the posttranslational modifications
Synthesis of insulin
Release of insulin
• Beta cells in the islets of Langerhans release insulin
• In response to increased blood glucose( phase 1 ,rapid)
• Is triggered independently of sugar. (Phase 2 , slow)
• Somewhat influenced by the autonomic nervous
Signal transduction
• Special transporter proteins in cell membranes for entrance of glucose
• Low levels of circulating insulin will prevent glucose from entering the cell
• Decrease in the sensitivity to insulin resulting in decreased glucose absorption
Type 1 diabetes
• Partly inherited and triggered by certain infections
• Loss of the insulin-producing β-cell of the islets of Langerhans
• T-cell mediated autoimmune attack• Juvenile diabetes• Environmental trigger• Medication: regular ,NPH insulin and synth
etic insulin analogs
Type 2 diabetes
• Insulin resistance
• Reduced insulin sensitivity
• The most common type
• Due to lifestyle factors and genetics
• Medications: oral medications that improve insulin sensitivity or reduce glucose production , often in combination
Gestational diabetes
• involving a combination of inadequate insulin secretion and responsiveness
• Resembles type 2 diabetes
• Occurs 2%–5% of pregnancies
• May improve or disappear after delivery
• 20%–50% of affected women develop type 2 diabetes develop later in life
Diabetic Nephropathy