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