Question 1

What is Insulin?

Accepted Answer

Insulin is a 51-amino acid peptide hormone produced by pancreatic beta cells that serves as the master regulator of glucose metabolism and the body's primary anabolic hormone. Consisting of two polypeptide chains (A-chain: 21 amino acids, B-chain: 30 amino acids) connected by two disulfide bonds, insulin was the first protein to have its structure determined (Frederick Sanger, Nobel Prize 1958) and the first therapeutic protein produced by recombinant DNA technology (1982). The discovery of insulin by Banting and Best in 1921 transformed type 1 diabetes from a fatal disease to a manageable condition, representing one of the most important medical breakthroughs of the 20th century. Today, over 500 million people worldwide depend on insulin therapy. Modern insulin analogs have been engineered for ultra-rapid, rapid, intermediate, and long-acting profiles to mimic physiological insulin secretion patterns.

Question 2

How does Insulin work?

Accepted Answer

Insulin binds to the insulin receptor (IR), a receptor tyrosine kinase, triggering autophosphorylation and recruitment of IRS proteins (IRS-1/2). This activates two major pathways: PI3K/Akt for metabolic effects (GLUT4 translocation, glycogen synthesis, lipogenesis, protein synthesis) and Ras/MAPK for mitogenic effects (cell growth and differentiation). In muscle and adipose tissue, Akt-mediated GLUT4 translocation to the cell surface enables glucose uptake — the primary mechanism of blood glucose reduction.

Question 3

What are the research applications of Insulin?

Accepted Answer

Type 1 Diabetes (Approved — Essential)

Insulin is essential for survival in type 1 diabetes and remains irreplaceable. Modern management uses multiple daily injections or continuous subcutaneous insulin infusion (pump therapy).

Type 2 Diabetes (Approved)

Used when oral agents and GLP-1RAs fail to achieve glycemic control. Basal insulin (glargine, detemir, degludec) is typically added first, with bolus insulin for advanced disease.

Smart Insulin Research

Glucose-responsive "smart" insulin formulations that automatically adjust activity based on blood glucose levels are in clinical development.

Closed-Loop Artificial Pancreas

Automated insulin delivery systems coupling continuous glucose monitors with insulin pumps represent the frontier of diabetes technology.

Question 4

What are the biological pathways affected by Insulin?

Accepted Answer

IR/IRS/PI3K/Akt/GLUT4 for glucose uptake. Akt/GSK-3β for glycogen synthesis. Akt/mTOR/p70S6K for protein synthesis. Akt/FOXO for gluconeogenesis suppression. SREBP-1c for lipogenesis. Ras/Raf/MEK/ERK for cell growth.

Question 5

What are the potential side effects of Insulin?

Accepted Answer

Hypoglycemia is the most significant risk — severe hypoglycemia can cause seizures, loss of consciousness, and death. Weight gain (2-4 kg) is common with insulin initiation. Injection site lipohypertrophy from repeated injection in same site. Hypokalemia from insulin-mediated potassium shift. Rare allergic reactions. Insulin edema during initial treatment. Peripheral edema.

Research Use Only. This information is for educational and research purposes only. Not intended for medical advice or self-medication.

Question 6

How should Insulin be stored?

Accepted Answer

Insulin must be stored at 2-8°C before opening. In-use insulin pens/vials can be stored at room temperature (up to 30°C) for 28-42 days depending on formulation. Never freeze. Sensitive to extreme heat and agitation. Modern analogs have improved stability profiles. Insulin is a relatively fragile protein requiring careful handling.

Question 7

What is the regulatory status of Insulin?

Accepted Answer

FDA-approved (multiple formulations): rapid-acting (lispro, aspart, glulisine), regular, intermediate (NPH), long-acting (glargine, detemir, degludec), ultra-long-acting, and premixed. Available worldwide. On WHO Essential Medicines List. WADA-prohibited unless medically prescribed for diagnosed diabetes.

Question 8

Where can I find research studies on Insulin?

Accepted Answer

Scientific studies on Insulin can be found in peer-reviewed journals through databases like PubMed and Google Scholar.

Question 9

What quality standards should Insulin meet for research?

Accepted Answer

Research-grade Insulin should meet high purity standards, typically >95% purity, with proper analytical certification and storage requirements.

Insulin